Hwan. 001

문제 1. 손익분기점

#include <iostream>

using namespace std;

int main() {
	int a, b, c;
	cin >> a >> b >> c;
	int unit_profit = c - b;

	if (unit_profit <= 0) {
		cout << -1;
	}
	else {
		cout << a / unit_profit +1 << endl;
	}
    
	return 0;
}


/*
* 반복으로 문제를 풀 경우 시간 초과 발생
*/

문제 2. 벌집

#include <iostream>

using namespace std;

int main() {
	int a;
	cin >> a;
	
	for (int i = 1; true; i++) {
		if (a == 1) {
			cout << i;
			break;
		}

		a -= (6 * i);
		
		if (a <= 0) {
			cout << i+1;
			break;
		}
	}

	return 0;
}

/*
* 각 껍질당 1 -> 6 -> 12 -> 18 ... 로 6 * i 형태로 올라감
* 입력 받은 수에서 6 * i 씩 감소시켜 몇 칸을 지나는지 알수있음
* , 1일 경우 출력 후 바로 종료
*/

문제 3. 분수찾기

#include <iostream>

using namespace std;

unsigned long long func_1193_sum_of_arithmetic_sequences(int n) {
	return ( n * (n+1) ) / 2;
}

string func_1193_create(int n) {
	// 입력받은 인덱스를 규칙을 기반으로 생성 (입력시마다 생성, 모든 수가 비슷한 시간)
	// 규칙. 칸 수가 내려갈수록 1개씩 증가 1-> 2 -> 3 -> 4 ... 그리고 a/b 가 a는 증가, b는 감소
	int lv, pos;
	int a, b;

	// 계층 구하기
	for (int i = 0; i < 10000; i++) {
		if (n <= func_1193_sum_of_arithmetic_sequences(i)) {
			lv = i;
			break;
		}
	}

	// 계층과 차이나는 위치값 구하기
	pos = n - func_1193_sum_of_arithmetic_sequences(lv);

	// 시작지점의 값 설정
	if (lv % 2 == 0) {
		a = 1;
		b = lv;
		pos *= -1;
	}
	else {
		a = lv;
		b = 1;
	}

	// 차이나는 값 만큼 보정
	a += pos;
	b -= pos;

	return to_string(b) + "/" + to_string(a);
}

int main() {
	int a;
	cin >> a;

	cout << func_1193_create(a) << endl;
	return 0;
}

문제 4. 달팽이는 올라가고 싶다

#include <iostream>

using namespace std;

int main() {
	long long a, b, v, day;
	cin >> a >> b >> v;

	if (v <= a) {
		day = 1;
	}
	else {
		day = (v - b) / (a - b);
		if ((v - b) % (a - b) > 0) {
			day++;
		}
	}

	cout << day << endl;
    
	return 0;
}

문제 5. ACM 호텔

#include <iostream>

using namespace std;

int main() {
	int a, h, w, n;
	int f, no;

	cin >> a;

	for (int i = 0; i < a; i++) {
		f = 1;
		no = 1;
		cin >> h >> w >> n;

		f += (n % h) -1;
		if (n % h == 0) {
			f = h;
			no = n / h;
		}
		else {
			no += (n / h);
		}

		printf("%d%02d\n", f , no);
	}
}

문제 6. 부녀회장이 될테야

#include <iostream>

using namespace std;

int func_2775_sum_people(int k, int n) {
	if (k == 0) return n;
	if (n == 1) return 1;
	return func_2775_sum_people(k, n - 1) + func_2775_sum_people(k-1, n);
}

int main() {
	int int_k, int_n, int_t;

	cin >> int_t;

	for (int i = 0; i < int_t; i++) {
		cin >> int_k;
		cin >> int_n;

		cout << func_2775_sum_people(int_k, int_n) << endl;
	}
    
    return 0;
}

문제 7. 설탕배달

#include <iostream>

using namespace std;

int main() {
	int a, b, n, min, tmp, res;
	bool is_flag;

	cin >> n;

	min = n;
	res = -1;
	is_flag = false;

	for (int a = 0; a < n; a++) {
		for (int b = 0; b < n; b++) {
			tmp = (3 * a) + (5 * b);

			if (tmp > n) break;
			if (tmp == n) {
				if (min >= a + b) {
					min = a + b;
					is_flag = true;
				}
			}
		}
	}

	if (is_flag) res = min;

	cout << res << endl;
}

문제 8. 큰수 A+B

#include <iostream>
#include <vector>

using namespace std;

vector<int> func_10757_reverseVector(string num) {
	vector<int> v;

	for (int i = num.length() - 1; i >= 0; i--) {
		v.push_back( (num[i] - '0'));
	}

	return v;
}

int main() {
	string str_a, str_b;
	cin >> str_a >> str_b;

	vector<int> a, b, c;
	int int_a, int_b, int_tmp = 0, int_len;

	a = func_10757_reverseVector(str_a);
	b = func_10757_reverseVector(str_b);

	if (a.size() >= b.size()) {
		int_len = a.size();
	}
	else {
		int_len = b.size();
	}


	for (int i = 0; i < int_len; i++) {
		try {
			int_a = a.at(i);
		}
		catch (exception e) {
			int_a = 0;
		}

		try {
			int_b = b.at(i);
		}
		catch (exception e) {
			int_b = 0;
		}

		c.push_back((int_a + int_b + int_tmp) % 10);

		if ((int_a + int_b + int_tmp) >= 10) {
			int_tmp = 1;
		}
		else {
			int_tmp = 0;
		}
	}

	if (int_tmp) {
		c.push_back(1);
	}

	for (int i = c.size() - 1; i >= 0; i--) {
		cout << c.at(i);
	}
    
    return 0;
}

문제 9. Fly me to the Alpha Centauri

#include <iostream>
#include <cmath>

using namespace std;

typedef unsigned long long ll;

int main() {
    int int_case;
	ll x, y;
	ll res;
	ll distance, level;
	cin >> int_case;

	for (int i = 0; i < int_case; i++) {
		cin >> x >> y;
		distance = y - x;

		if (distance > 0 && distance <= 3) {
			res = distance;
		}
		else {
			level = (int)sqrt(distance);

			if (((level + 1) * (level + 1)) - (level+1) < distance && distance < ((level + 1) * (level + 1))) {
				res = 2 * level+1;
			}
			else if (distance == level * level ) {
				res = 2 * level -1;
			}
			else {
				res = 2 * level;
			}
		}

		cout << res << "\n";
	}
    return 0;
}

결과

문제 1. 아스키 코드

#include <iostream>

using namespace std;

int main() {
    cin.tie(NULL);
    cin.sync_with_stdio(false);

    char a;
    cin >> a;
    cout << int(a) << endl;

    return 0;
}

문제 2. 숫자의 합

#include <iostream>
#include <string>

using namespace std;

int main() {
    cin.tie(NULL);
    cin.sync_with_stdio(false);

    int a, sum=0;
    string b;
    cin >> a >> b;

    for (int i = 0; i < a; i++) {
        sum += int(b[i]) - int('0');
    }

    cout << sum << endl;

    return 0;
}

문제 3. 알파벳 찾기

#include <iostream>
#include <string>

using namespace std;

int main() {
    string s;
    int alphabets[26], index;
    int arr_size = sizeof(alphabets) / sizeof(int);

    for (int i = 0; i < arr_size; i++) {
        alphabets[i] = -1;
    }

    cin >> s;
    for (int i=0; i < s.size(); i++) {
        index = int(s[i]) - int('a');
        if (alphabets[index] == -1) {
            alphabets[index] += (i + 1);
        }
    }

    for (int i = 0; i < arr_size; i++) {
        cout << alphabets[i];
        if (i != arr_size - 1) cout << " ";
    }

    return 0;
}

문제 4. 문자열 반복

#include <iostream>

using namespace std;

int main(){
    int a, b;
	string str;

	cin >> a;

	for (int i = 0; i < a; i++) {
		cin >> b >> str;
		for (int i = 0; i < str.length(); i++) {
			for (int j = 0; j < b; j++) {
				cout << str[i];
			}
		}
		cout << endl;
	}
    
    return 0;
}

문제 5. 단어 공부

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <map> 
#include <utility>

using namespace std;

int main() {
	string str;
	map<char, int> myMap;
	map<char, int>::iterator iter;

	int int_max = 0;

	char ch_result;
	int int_cnt = 0;

	for (char c = 'a'; c <= 'z'; c++) {
		myMap[c] == 0;
	}

	cin >> str;
	for (int i = 0; i < str.length(); i++) {
		str[i] = tolower(str[i]);
		myMap[str[i]]++;
	}

	for (iter = myMap.begin(); iter != myMap.end(); iter++) {
		if (iter->second > int_max) {
			int_max = iter->second;
		}
	}

	for (iter = myMap.begin(); iter != myMap.end(); iter++) {
		if (int_max == iter->second) {
			int_cnt++;
			ch_result = iter->first;
		}
	}

	if (int_cnt == 1) {
		printf("%c\n", toupper(ch_result));
	}
	else {
		cout << '?' << endl;
	}

	return 0;
}

문제 6. 단어의 개수

#include <iostream>
#include <vector>
#include <string>
#include <sstream> 

using namespace std;

vector<string> func_1152_split(string str, char ch) {
	stringstream ss(str);
	string tmp;
	vector<string> res;

	while (getline(ss, tmp, ch)) {
		res.push_back(tmp);
	}

	return res;
}

int main() {
	string str;
	vector<string> res;
	int cnt = 0;

	getline(cin, str, '\n');
	res = func_1152_split(str, ' ');

	for (int i = 0; i < res.size(); i++) {
		if (res[i].size() > 0) cnt++;
	}

	cout << cnt << endl;
    return 0;
}

문제 7. 상수

#include<iostream>
#include<string>

using namespace std;

int main(){
	string a, b;
	string a_r, b_r;
	int res;
	int cnt=0;

	cin >> a >> b;

	a_r = a;
	b_r = b;

	for (int i = 2; i >= 0; i--) {
		a_r[cnt] = a[i];
		b_r[cnt++] = b[i];
	}
	
	if (stoi(a_r) > stoi(b_r)) {
		res = stoi(a_r);
	}
	else {
		res = stoi(b_r);
	}

	cout << res ;
    
    return 0;
}

문제 8. 다이얼

#include <iostream>
#include <string>
#include <map>

using namespace std;

int main(){
    string str;
	cin >> str;
	map<char, int> m;
	int point, sum=0;

	for (int i = 0; i < 26; i++) {	
		if ('A' + i < 'Z') point = 10;
		if ('A' + i < 'W') point = 9;
		if ('A' + i < 'T') point = 8;
		if ('A' + i < 'P') point = 7;
		if ('A' + i < 'M') point = 6;
		if ('A' + i < 'J') point = 5;
		if ('A' + i < 'G') point = 4;
		if ('A' + i < 'D') point = 3;

		m['A' + i] = point;
	}

	for (int i = 0; i < str.length(); i++) {
		sum += m[str[i]];
	}

	cout << sum << endl;
    
    return 0;
}

문제 9. 크로아티아 알파벳

#include <iostream>
#include <vector>
#include <string>

using namespace std;

int main() {
 	vector<string> v_str = { "c=", "c-", "dz=", "d-", "lj", "nj", "s=", "z=" };
	string str;

	cin >> str;
	for (int i = 0; i < v_str.size(); i++) {
		while (1) {
			if (str.find(v_str[i]) == string::npos) {
				break;
			}
			else {
				str.replace(str.find(v_str[i]), v_str[i].length(), "!");
			}
		}
	}

	cout << str.length() << endl;
    return 0;
}

문제 10. 그룹 단어 체커

#include <iostream>
#include <string>
#include <map> 

using namespace std;

int main() {
    	int a;
	cin >> a;

	string* arr_str = new string[a];
	map<char, int> m;
	int cnt = 0;

	for (int i = 0; i < a; i++) {
		cin >> arr_str[i];
	}

	char pre_ch;
	bool is_flag;

	for (int i = 0; i < a; i++) {
		pre_ch = '0';
		is_flag = true;
		for (char ch = 'a'; ch <= 'z'; ch++) {
			m[ch] = 0;
		}

		for (int j = 0; j < arr_str[i].length(); j++) {
			if (m[arr_str[i][j]] != 0) {
				if (pre_ch != arr_str[i][j]) {
					is_flag = false;
					break;
				}
			}

			m[arr_str[i][j]]++;
			pre_ch = arr_str[i][j];
		}

		if (is_flag) {
			cnt++;
		}
	}
	
	cout << cnt;
	return 0;
}

결과

문제 1. 정수 N개의 합

#include <vector>

using namespace std;

long long sum(vector<int>& a) {
	long long ans = 0;

	for (int i = 0; i < a.size(); i++) {
		ans += a.at(i);
	}

	return ans;
}

문제 2. 셀프 넘버 

#include <iostream>
#include <string>
#include <cmath>

using namespace std;

int selfnumber(int a) {
    int digit = to_string(a).size(), tmp = 0, a_copy = a, sum = a;
    int* arr = new int[digit];
    
    for (int i = 0; i < digit; i++) {
        tmp = pow(10, (digit - (i + 1)));
        arr[i] = a_copy / tmp;
        a_copy %= tmp;
    }
    
    for (int i = 0; i < digit; i++) {
        sum += arr[i];
    }

    return sum;
}

int main() {
    int a = 10000;

    cin.tie(NULL);
    cin.sync_with_stdio(false);

    int* arr = new int[a];
    for (int i = 0; i < a; i++) {
        arr[i] = 0;
    }

    for (int i = 0; i < a; i++) {
        arr[selfnumber(i)-1]++;
    }

    for (int i = 0; i < a; i++) {
        if (arr[i] == 0) {
            cout << i+1 << endl;
        }
    }
    return 0;
}

문제 3. 한수

#include <iostream>
#include <string>
#include <cmath>

using namespace std;

bool hansu(int a) {
    bool is_flag = false;
    int tmp, cnt = 0;
    int digit = to_string(a).size();

    if (digit > 2) {
        int* arr = new int[digit];

        for (int i = 0; i < digit; i++) {
            tmp = pow(10, (digit - (i + 1)));
            arr[i] = a / tmp;
            a %= tmp;
        }

        int now_dif = 0;
        int pre_dif = arr[0] - arr[1];

        for (int i = 0; i < digit - 1; i++) {
            now_dif = arr[i] - arr[i + 1];
            if (now_dif == pre_dif) cnt++;
            pre_dif = now_dif;
        }

        if (digit - 1 == cnt) {
            is_flag = true;
        }
    }
    else {
        is_flag = true;
    }
    return is_flag;
}

int main() {
    int a = 0, cnt = 0;

    cin.tie(NULL);
    cin.sync_with_stdio(false);

    cin >> a;

    for (int i = 1; i <= a; i++) {
        if (hansu(i)) cnt++;
    }
    
    cout << cnt << endl;
    
    return 0;
}

결과

문제 1. 최소, 최대

#include <iostream>
#include <vector>

using namespace std;

int min(vector<int>& arr) {
    int min = arr.front();

    for (int i = 0; i < arr.size(); i++) {
        if (arr.at(i) < min) {
            min = arr.at(i);
        }
    }

    return min;
}

int max(vector<int>& arr) {
    int max = arr.front();

    for (int i = 0; i < arr.size(); i++) {
        if (arr.at(i) > max) {
            max = arr.at(i);
        }
    }

    return max;
}

int main() {
    int a, tmp;
    vector<int> arr;

    cin >> a;

    for (int i = 0; i < a; i++){
        cin >> tmp;
        arr.push_back(tmp);
    }

    cout << min(arr) << " " << max(arr);

    return 0;
}

문제 2. 최댓값

#include <iostream>
#include <vector>

using namespace std;

int main() {
    int tmp, max;
    vector<int> arr;

    for (int i = 0; i < 9; i++){
        cin >> tmp;
        arr.push_back(tmp);
    }

    max = arr.front();

    for (int i = 0; i < arr.size(); i++) {
        if (arr.at(i) >= max) {
            max = arr.at(i);
            tmp = i+1;
        }
    }

    cout << max << endl;
    cout << tmp;

    return 0;
}

문제 3. 숫자의 개수

#include <iostream>
#include <string>

using namespace std;

int main() {
    int a, b, c;
    int arr[10] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; 
    string str_abc;

    cin >> a >> b >> c;
    str_abc = to_string(a * b * c);

    for (int i = 0; i < str_abc.length(); i++) {
        arr[int(char(str_abc[i])) - int('0')]++;
    }

    for (int i = 0; i < 10; i++) {
        cout << arr[i] << endl;
    }

    return 0;
}

문제 4. 나머지

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    vector<int> arr;
    int a;

    for (int i = 0; i < 10; i++) {
        cin >> a;
        arr.push_back(a % 42);
    }

    sort(arr.begin(), arr.end());
    arr.erase(unique(arr.begin(), arr.end()), arr.end());

    cout << arr.size() << endl;
    return 0;
}

문제 5. 평균

#include <iostream>

using namespace std;

int main() {
    int a, max;
    double aver=0;

    cin >> a;
    int* arr = new int[a];
    double* arr2 = new double[a];

    for (int i = 0; i < a; i++) {
        cin >> arr[i];

        if (i == 0) {
            max = arr[0];
        }

        if (arr[i] > max) {
            max = arr[i];
        }
    }

    for (int i = 0; i < a; i++) {
        arr2[i] = double(arr[i]) / max * 100;
    }

    for (int i = 0; i < a; i++) {
        aver += arr2[i];
    }

    cout.precision(6);
    cout << aver / a << endl;

    return 0;
}

문제 6. OX퀴즈

#include <iostream>

using namespace std;

int point(string str) {
    bool is_flag = false;
    int cnt = 1, sum = 0;

    for (int i = 0; i <= str.size(); i++) {
        if (str[i] == 'O') {
            if(is_flag) cnt++;
            is_flag = true;
            sum += cnt;
        }
        else {
            cnt = 1;
            is_flag = false;
        }
    }

    return sum;
}

int main() {
    int a;
    cin >> a;
    int* arr = new int[a];
    string* str_arr = new string[a];

    for (int i = 0; i < a; i++) {
        cin >> str_arr[i];
    }

    for (int i = 0; i < a; i++) {
        cout << point(str_arr[i]) << endl;
    }

    return 0;
}

문제 7. 평균은 넘겠지

#include <iostream>
#include <vector>
#include <stdio.h>

using namespace std;

int main() {
    int a, b, sum, cnt, all;
    double aver;
    cin >> a;
    vector<int *> vec;
    char str_tmp[100];
    
    for (int i = 0; i < a; i++) {
        cin >> b;
        int* arr = new int[b + 1];
        arr[0] = b;

        for (int j = 1; j <= b; j++) {
            cin >> arr[j];
        }

        vec.push_back(arr);
    }

    for (int i = 0; i < vec.size(); i++) {
        all = int(vec.at(i)[0]); 
        sum = 0;
        for (int j = 1; j <= all; j++) {
            sum += vec.at(i)[j];
        }
        aver = double(sum) / all;

        cnt = 0;
        for (int j = 1; j <= all; j++) {
            if (aver < vec.at(i)[j]) {
                cnt += 1;
            }
        }
        
        sprintf(str_tmp, "%.3f", double(cnt) / all * 100);
        cout << str_tmp << "%" << endl;
    }
    
    return 0;
}

결과

문제 1. A+B - 5

#include <iostream>

using namespace std;

int main() {
    int a, b;

    while (true) {
        cin >> a >> b;

        if (a + b == 0) {
            break;
        }

        cout << a + b << endl;
    }
    
    return 0;
}

문제 2. A+B - 4

#include <iostream>

using namespace std;

int main() {
    int a, b;

    while (cin >> a >> b) {
        cout << a + b << endl;
    }
    
    return 0;
}

문제 3. 더하기 사이클

#include <iostream>

using namespace std;

void func(int a, int *front, int *back) {
    if (a < 10) {
        if(front) *front = 0;
        if(back) *back = a;
    }
    else {
        if (front) *front = a / 10;
        if (back) *back = a % 10;
    }
}

int main() {
    int a, b, cycle = 0;
    int front_a, back_a, back_b;

    cin >> a;
    b = a;

    do {
        func(b, &front_a, &back_a);
        func(front_a + back_a, NULL, &back_b);
        
        b = back_a * 10 + back_b;
        
        cycle++;
    } while (a != b);

    cout << cycle;

    return 0;
}

결과

문제 1. 구구단

#include <iostream>

using namespace std;

int main() {
    int a;

    cin >> a;

    for (int i=1; i<10; i++) {
        cout << a << " * " << i << " = " << a * i << endl;
    }

    return 0;
}

문제 2. A+B - 3

#include <iostream>

using namespace std;

int main() {
    int cnt=0, a, b;

    cin >> cnt;
    int *arr = new int[cnt];

    for (int i = 0; i < cnt; i++) {
        cin >> a >> b;
        arr[i] = a + b;
    }

    for (int i = 0; i < cnt; i++) {
        cout << arr[i] << endl;
    }

    return 0;
}

문제 3. 합

#include <iostream>

using namespace std;

int main() {
    int a, sum=0;

    cin >> a;

    for (int i = 1; i <= a; i++) {
        sum += i;
    }

    cout << sum;

    return 0;
}

문제 4. 빠른 A+B

#include <iostream>

using namespace std;

int main() {
    int cnt = 0, a, b;

    cin.tie(NULL);
    cin.sync_with_stdio(false);

    cin >> cnt;
    int* arr = new int[cnt];

    for (int i = 0; i < cnt; i++) {
        cin >> a >> b;
        arr[i] = a + b;
    }

    for (int i = 0; i < cnt; i++) {
        cout << arr[i] << "\n";
    }

    return 0;
}

문제 5. N 찍기

#include <iostream>

using namespace std;

int main() {
    int cnt = 0;

    cin.tie(NULL);
    cin.sync_with_stdio(false);

    cin >> cnt;

    for (int i = 1; i <= cnt; i++) {
        cout << i << "\n";
    }

    return 0;
}

문제 6. 기찍 N

#include <iostream>

using namespace std;

int main() {
    int cnt = 0;

    cin.tie(NULL);
    cin.sync_with_stdio(false);

    cin >> cnt;

    for (int i = cnt; i > 0; i--) {
        cout << i << "\n";
    }

    return 0;
}

문제 7. A+B - 7

#include <iostream>

using namespace std;

int main() {
    int cnt = 0, a, b;

    cin >> cnt;
    int* arr = new int[cnt];

    for (int i = 0; i < cnt; i++) {
        cin >> a >> b;
        arr[i] = a + b;
    }

    for (int i = 0; i < cnt; i++) {
        cout << "Case #" << i+1 << ": "<< arr[i] << endl;
    }

    return 0;
}

문제 8. A+B - 8

#include <iostream>

using namespace std;

int main() {
    int cnt = 0;

    cin >> cnt;
    int* arr = new int[cnt];
    int* a = new int[cnt];
    int* b = new int[cnt];

    for (int i = 0; i < cnt; i++) {
        cin >> a[i] >> b[i];
        arr[i] = a[i] + b[i];
    }

    for (int i = 0; i < cnt; i++) {
        cout << "Case #" << i+1 << ": " << a[i] << " + " << b[i] << " = " << arr[i] << endl;
    }

    return 0;
}

문제 9. 별 찍기 - 1

#include <iostream>

using namespace std;

int main() {
    int cnt = 0;

    cin >> cnt;

    for (int i = 0; i < cnt; i++) {
        for (int j = 0; j <= i; j++) {
            cout << "*";
        }
        cout << "\n";
    }

    return 0;
}

문제 10. 별 찍기 - 2

#include <iostream>

using namespace std;

int main() {
    int cnt = 0;

    cin >> cnt;

    for (int i = 1; i <= cnt; i++) {
        for (int j = cnt; j >= 1; j--) {
            if (i < j) {
                cout << " ";
            }
            else {
                cout << "*";
            }
        }
        cout << "\n";
    }

    return 0;
}

문제 11. X보다 작은 수

#include <iostream>

using namespace std;

int main() {
    int n, x;
    cin >> n >> x;

    int* arr = new int[n];

    for (int i = 0; i < n; i++) {
        cin >> arr[i];
    }

    for (int i = 0; i < n; i++) {
        if (arr[i] < x) {
            cout << arr[i];
            if (i != n - 1) {
                cout << " ";
            }
        }
    }


    return 0;
}

결과

문제 1. 두 수 비교하기

#include <iostream>

using namespace std;

int main() {
    int a, b;

    cin >> a;
    cin >> b;

    if (a > b) {
        cout << ">";
    }
    else if (a < b) {
        cout << "<";
    }
    else {
        cout << "==";
    }

    return 0;
}

문제 2. 시험 성적

#include <iostream>

using namespace std;

int main() {
    int a;
    string b = "F";

    cin >> a;

    if (a >= 60) {
        b = "D";
    }
    if (a >= 70) {
        b = "C";
    }
    if (a >= 80) {
        b = "B";
    }
    if (a >= 90) {
        b = "A";
    }

    cout << b;

    return 0;
}

문제 3. 윤년

#include <iostream>

using namespace std;

int main() {
    int a, answer = 0;
    cin >> a;

    if(a % 4 == 0 && a % 100 != 0) {
        answer = 1;
    }
    if (a % 400 == 0) {
        answer = 1;
    }

    cout << answer;

    return 0;
}

문제 4. 사분면 고르기

#include <iostream>

using namespace std;

int main() {
    int x, y, answer = 0;
    cin >> x;
    cin >> y;

    if (x > 0 && y > 0) {
        answer = 1;
    }
    if (x < 0 && y > 0) {
        answer = 2;
    }
    if (x < 0 && y < 0) {
        answer = 3;
    }
    if (x > 0 && y < 0) {
        answer = 4;
    }

    cout << answer;

    return 0;
}

문제 5. 알람 시계

#include <iostream>
#include <stdio.h>

using namespace std;

int main() {
    int h, m;
    char answer[30] = "";

    cin >> h;
    cin >> m;

    m -= 45;

    if (m >= 60) {
        m -= 60;
        h += 1;
    }
    if (m < 0) {
        m = 60 + m;
        h -= 1;
    }

    if (h >= 24) {
        h -= 24;
    }
    if (h < 0) {
        h = 24 + h;
    }

    snprintf(answer, 30, "%d %d", h, m);
    cout << answer;

    return 0;
}

추가 문제 6. 오븐 시계 (브론즈 4, 2022-02-16 확인)

#include<iostream>

using namespace std;

int main() {
	int a, b, c;
	cin >> a >> b >> c;

	b = b + c;
	if (b < 0) {
		b = 0;
	}
	while (b >= 60) {
		b -= 60;
		a += 1;
	}

	if (a < 0) {
		a = 0;
	}
	while (a >= 24) {
		a -= 24;
	}

	cout << a << " " << b << "\n";
    
    return 0;
}

추가 문제 7. 주사위 세개(브론즈 4, 2022-02-16)

#include<iostream>
#include<map>

using namespace std;

int main() {
	map<int, int> m;
	int a, res=0, k_max = 0, v_max = 0;

	for (int i = 0; i < 3; i++) {
		cin >> a;
		m[a]++;
		if (k_max < a) k_max = a;
		if (v_max < m[a]) v_max = m[a];
	}

	for (auto v : m) {
		if (v_max != 1 && v_max == v.second) {
			k_max = v.first;
		}
	}

	if (v_max == 3) {
		res = 10000 + k_max * 1000;
	}
	if (v_max == 2) {
		res = 1000 + k_max * 100;
	}
	if (v_max == 1) {
		res = k_max * 100;
	}

	cout << res << "\n";
    
    return 0;
}

결과

문제 1. Hello World

#include <iostream>

int main(){
    std::cout << "Hello World!";
    
    return 0;
}

문제 2. We love krill

#include <iostream>

int main(){
    std::cout << "강한친구 대한육군";
    std::cout << "강한친구 대한육군";
    
    return 0;
}

문제 3. 고양이

#include <iostream>

using namespace std;

int main() {
    cout << "\\    /\\\n";
    cout << " )  ( ')\n";
    cout << "(  /  )\n";
    cout << " \\(__)|\n";
    
    return 0;
}

문제 4. 개

#include <iostream>
using namespace std;

int main(){
    cout << "|\\_/|\n";
    cout << "|q p|   /}\n";
    cout << "( 0 )\"\"\"\\\n";
    cout << "|\"^\"`    |\n";
    cout << "||_/=\\\\__|\n";
    
    return 0;
}

문제 5. A+B

int main(){
    int a, b;
    
    scanf("%d %d", &a, &b);
    printf("%d", a+b);
    
    return 0;
}

문제 6. A-B

int main(){
    int a, b;
    
    scanf("%d %d", &a, &b);
    printf("%d", a-b);
    
    return 0;
}

문제 7. A*B

#include <iostream>

int main(){
    int A, B;
    
    std::cin >> A >> B;
    std::cout << A * B;
    
    return 0;
}

문제 8. A/B

#include <iostream>

using namespace std;

int main() {
    double a, b;
    cin >> a >> b;
    
    printf("%.10f", a / b);

    return 0;
}

문제 9. 사칙연산

#include <iostream>

using namespace std;

int main() {
    int a, b;
    cin >> a >> b;
    
    cout << a + b << endl;
    cout << a - b << endl;
    cout << a * b << endl;
    cout << a / b << endl;
    cout << a % b << endl;

    return 0;
}

문제 10. 나머지

#include <iostream>

using namespace std;

int main() {
    int a, b, c;
    cin >> a >> b >> c;
    
    cout << (a + b) % c << endl;
    cout << ((a%c) + (b%c))%c << endl;
    cout << (a * b)%c << endl;
    cout << ((a % c) * (b % c)) % c << endl;

    return 0;
}

문제 11. 곱셈

#include <iostream>

using namespace std;

int main() {
    int a, b, c;
    int b1, b2, b3;

    cin >> a;
    cin >> b;

    c = a * b;
    b3 = a * (b / 100);
    b %= 100;
    b2 = a * (b / 10);
    b %= 10;
    b1 = a * b; 

    cout << b1 << endl;
    cout << b2 << endl;
    cout << b3 << endl;
    cout << c << endl;

    return 0;
}

결과