Submission #210006

#	Time	Username	Problem	Language	Result	Execution time	Memory
210006		SamAnd	Zapina (COCI20_zapina)	C++17	110 / 110	71 ms	5752 KiB

zapina

#include <bits/stdc++.h>
using namespace std;
const int N = 1003;
const int M = 1000000007;

int n;

int c[N][N];
int dp[N][N];
int dp1[N][N];
//int dp11[N][N];

int main()
{
    for (int i = 0; i < N; ++i)
    {
        c[i][0] = 1;
        for (int j = 1; j <= i; ++j)
            c[i][j] = (c[i - 1][j] + c[i - 1][j - 1]) % M;
    }
    scanf("%d", &n);
    dp[0][0] = 1;
    for (int x = 1; x <= n; ++x)
    {
        for (int i = n; i >= 0; --i)
        {
            for (int j = n; j >= 0; --j)
            {
                if (!dp[i][j])
                    continue;
                if (j + x <= n)
                    dp[i + 1][j + x] = (dp[i + 1][j + x] + (dp[i][j] * 1LL * c[n - j][x]) % M) % M;
            }
        }
    }
    /*for (int j = 0; j <= n; ++j)
    {
        for (int i = 0; i <= n; ++i)
            for (int k = 0; k <= j; ++k)
                dp11[i][k] = 0;
        dp11[0][0] = 1;
        for (int i = 1; i <= n; ++i)
        {
            for (int k = 0; k <= j; ++k)
            {
                for (int q = 0; q <= k; ++q)
                {
                    dp11[i][k] = (dp11[i][k] + (dp11[i - 1][k - q] * 1LL * c[k][q]) % M) % M;
                }
            }
        }
        for (int i = 0; i <= n; ++i)
            dp1[i][j] = dp11[i][j];
    }*/
    for (int i = 0; i <= n; ++i)
    {
        dp1[i][0] = 1;
        for (int j = 1; j <= n; ++j)
            dp1[i][j] = (dp1[i][j - 1] * 1LL * i) % M;
    }
    int ans = 0;
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= n; ++j)
        {
            if (i % 2 == 1)
            {
                ans = (ans + (dp[i][j] * 1LL * dp1[n - i][n - j]) % M) % M;
            }
            else
            {
                ans = (ans - (dp[i][j] * 1LL * dp1[n - i][n - j]) % M + M) % M;
            }
        }
    }
    printf("%d\n", ans);
    return 0;
}

Compilation message (stderr)

zapina.cpp: In function 'int main()':
zapina.cpp:21:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 33 / 33
• Subtask 3: 55 / 55