cf每日刷题c++

2025-06-01 01:01:38 3 阅读

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

Fashionable Array（800）

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

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

Game of Mathletes(900)

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

#include 
#include 
#include 
using namespace std;
void solve()
{
    int n, k;
    cin >> n >> k;
    vector 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 << "
";
}
int main()
{
    int t;
    cin >> t;
    while (t--)
    {
        solve();
    }
    return 0;
}

LRC and VIP(800)

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

#include 
#include 
#include 
using namespace std;
void solve()
{
    int n;
    cin >> n;
    vector 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
";
        return;
    }
    cout << "YES
";
    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;
}