cf每日刷题c++

Simple Repetition（1000）

Fashionable Array（800）

Kevin and Arithmetic(800)

Permutation Warm-Up(800)

Game of Mathletes(900)

LRC and VIP(800)

Simple Repetition（1000）

https://codeforces.com/problemset/problem/2093/C

#include <iostream>
using namespace std;
void solve()
{int n, k;cin >> n >> k;if (n == 1){if (k == 2){cout << "YES\n";return;}cout << "NO\n";return;}if (k > 1){cout << "NO\n";return;}for (int i = 2; i * i <= n; i++){if (n % i == 0){cout << "NO\n";return;}}cout << "YES\n";return;
}
int main()
{int t;cin >> t;while (t--){solve();}return 0;
}

Fashionable Array（800）

https://codeforces.com/problemset/problem/2110/A

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void solve()
{int n;cin >> n;vector<int> a(n);for (int i = 0; i < n; i++){cin >> a[i];}sort(a.begin(), a.end());int l = 0;int r = a.size() - 1;int res = 0;while (l <= r){if ((a[r] - a[l]) % 2 != 0){l++;res++;}else{break;}}int L = 0;int R = a.size() - 1;int RES = 0;while (L <= R){if ((a[R] - a[L]) % 2 != 0){R--;RES++;}else{break;}}cout << min(res, RES) << endl;
}
int main()
{int t;cin >> t;while (t--){solve();}return 0;
}

Kevin and Arithmetic(800)

https://codeforces.com/problemset/problem/2061/A

#include <iostream>
using namespace std;
#include <vector>
#define int long long
void solve()
{int res = 0;int n;cin >> n;vector<int> a(n);int flag = 0;for (int i = 0; i < n; i++){cin >> a[i];if (a[i] % 2 == 0){flag = 1;}}if (flag){res++;for (int i = 0; i < n; i++){if (a[i] % 2 == 1){res++;}}}else{res = a.size() - 1;}cout << res << endl;
}
signed main()
{int t;cin >> t;while (t--){solve();}return 0;
}

Permutation Warm-Up(800)

https://codeforces.com/problemset/problem/2108/A

#include <iostream>
using namespace std;
void solve()
{int n;cin >> n;cout << n * n / 4 + 1 << "\n";
}
int main()
{int t;cin >> t;while (t--){solve();}return 0;
}

Game of Mathletes(900)

https://codeforces.com/problemset/problem/2060/C

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void solve()
{int n, k;cin >> n >> k;vector<int> a(n);for (int i = 0; i < n; i++){cin >> a[i];}sort(a.begin(), a.end());int res = 0;int l = 0;int r = a.size() - 1;while (l < r){if (a[l] + a[r] == k){res++;r--;l++;}if (a[l] + a[r] < k){l++;}if (a[l] + a[r] > k){r--;}}cout << res << "\n";
}
int main()
{int t;cin >> t;while (t--){solve();}return 0;
}

LRC and VIP(800)

https://codeforces.com/problemset/problem/2107/A

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void solve()
{int n;cin >> n;vector<int> a(n);int p = 0;bool flag = false;for (int i = 0; i < n; i++){cin >> a[i];if (a[i] > a[p]){p = i;}if (i >= 1){if (a[i] != a[i - 1]){flag = true;}}}if (!flag){cout << "NO\n";return;}cout << "YES\n";for (int i = 0; i < n; i++){if (i == p){cout << 1 << " ";}else{cout << 2 << " ";}}
}
int main()
{int t;cin >> t;while (t--){solve();}return 0;
}