#include <iostream>
#include <algorithm>

using namespace std;

const int N = 1010;

int n, m;
int v[N], w[N];
int f[N];

int main()
{
    cin >> n >> m;
    for (int i = 1; i <= n; i ++ ) cin >> v[i] >> w[i];

    for (int i = 1; i <= n; i ++ )
        for (int j = v[i]; j <= m; j ++ )
            f[j] = max(f[j], f[j - v[i]] + w[i]);

    cout << f[m] << endl;

    return 0;
}

#include <iostream>
#include <algorithm>

using namespace std;

const int N = 1010;

int n, m;
int v[N], w[N];
int f[N];

int main()
{
    cin >> n >> m;

    for (int i = 1; i <= n; i ++ ) cin >> v[i] >> w[i];

    for (int i = 1; i <= n; i ++ )
        for (int j = m; j >= v[i]; j -- )
            f[j] = max(f[j], f[j - v[i]] + w[i]);

    cout << f[m] << endl;

    return 0;
}

#include <iostream>
#include <cstring>
#include <algorithm>

using namespace std;

const int N = 21, M = 1000010, MOD = 1e9;

int m;
int f[M];

int main()
{
    scanf("%d", &m);
    f[0] = 1;

    for (int i = 1; i <= m; i *= 2)
        for (int j = i; j <= m; j ++ )
            f[j] = (f[j] + f[j - i]) % MOD;
 printf("%d\n", f[m]);
    return 0;
}

//判断输入内容有几个字符，有几个数字

include[HTML_REMOVED]

using namespace std;

int main()
{
char c;

int nums = 0,chars = 0;
while(cin >> c)
{
if (c >= ‘0’ && c <= ‘9’) nums;
else if (c >=’A’ && c <=’z’ || c >= ‘a’ && c <=’z’ )chars ;
}

printf(“nums: %d\nchars: %d\n”,nums,chars);

return 0;
}

#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

typedef long long LL;

const int N = 1000010;

int primes[N], cnt;
bool st[N];

void init(int n)
{
    memset(st, 0, sizeof st);
    cnt = 0;
    for (int i = 2; i <= n; i ++ )
    {
        if (!st[i]) primes[cnt ++ ] = i;
        for (int j = 0; primes[j] * i <= n; j ++ )
        {
            st[i * primes[j]] = true;
            if (i % primes[j] == 0) break;
        }
    }
}

int main()
{
    int l, r;
    while (cin >> l >> r)
    {
        init(50000);

        memset(st, 0, sizeof st);
        for (int i = 0; i < cnt; i ++ )
        {
            LL p = primes[i];
            for (LL j = max(p * 2, (l + p - 1) / p * p); j <= r; j += p)
                st[j - l] = true;
        }

        cnt = 0;
        for (int i = 0; i <= r - l; i ++ )
            if (!st[i] && i + l >= 2)
                primes[cnt ++ ] = i + l;

        if (cnt < 2) puts("There are no adjacent primes.");
        else
        {
            int minp = 0, maxp = 0;
            for (int i = 0; i + 1 < cnt; i ++ )
            {
                int d = primes[i + 1] - primes[i];
                if (d < primes[minp + 1] - primes[minp]) minp = i;
                if (d > primes[maxp + 1] - primes[maxp]) maxp = i;
            }

            printf("%d,%d are closest, %d,%d are most distant.\n",
                primes[minp], primes[minp + 1],
                primes[maxp], primes[maxp + 1]);
        }
    }

    return 0;
}

#include <iostream>
#include <algorithm>

using namespace std;

const int N= 1000010;

int primes[N], cnt;
bool st[N];

void get_primes(int n)
{
    for (int i = 2; i <= n; i ++ )
    {
        if (st[i]) continue;
        primes[cnt ++ ] = i;
        for (int j = i + i; j <= n; j += i)
            st[j] = true;
    }
}

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

    get_primes(n);

    cout << cnt << endl;

    return 0;
}

#include <iostream>
#include <cstring>
#include <algorithm>


using namespace std;

const int N = 1010;

int primes[N], cnt;
int sum[N];
bool st[N];

void get_primes(int n)
{
    for (int i = 2; i <= n; i ++ )
    {
        if (!st[i]) primes[cnt ++ ] = i;
        for (int j = 0; primes[j] * i <= n; j ++ )
        {
            st[primes[j] * i] = true;
            if (i % primes[j] == 0) break;
        }
    }
}

int main()
{
    int T;
    scanf("%d", &T);

    get_primes(N - 1);

    for (int i = 1; i < cnt; i ++ )
    {
        int s = primes[i] + primes[i - 1] + 1;
        if (s < N && !st[s])
            sum[s] = 1;
    }

    for (int i = 1; i < N; i ++ ) sum[i] += sum[i - 1];

    while (T -- )
    {
        int n, k;
        scanf("%d%d", &n, &k);
        if (sum[n] >= k) puts("YES");
        else puts("NO");
    }

    return 0;
}

#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

const int N = 5010;

int n, m;
int s[N][N];

int main()
{
    int cnt, R;
    cin >> cnt >> R;
    R = min(5001, R);

    n = m = R;
    while (cnt -- )
    {
        int x, y, w;
        cin >> x >> y >> w;
        x ++, y ++ ;
        n = max(n, x), m = max(m, y);
        s[x][y] += w;
    }

    // 预处理前缀和
    for (int i = 1; i <= n; i ++ )
        for (int j = 1; j <= m; j ++ )
            s[i][j] += s[i - 1][j] + s[i][j - 1] - s[i - 1][j - 1];

    int res = 0;

    // 枚举所有边长是R的矩形，枚举(i, j)为右下角
    for (int i = R; i <= n; i ++ )
        for (int j = R; j <= m; j ++ )
            res = max(res, s[i][j] - s[i - R][j] - s[i][j - R] + s[i - R][j - R]);

    cout << res << endl;

    return 0;
}

2023.02.12.11.53

import java.util.Scanner;

public class Main{
    private static int fact(int n){
        int res = 1;
        for (int i = 1;i<=n; i++)
            res*=i;
        return res;    
    }
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        System.out.println(fact(n));
    }
}

2.12

import java.util.Scanner;

public class Main{
    private static int fact(int n){
        int res = 1;
        for (int i = 1;i<=n; i++)
            res*=i;
        return res;    
    }
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        System.out.println(fact(n));
    }
}