Submission #37411837

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Source Code Expand

#include<bits/stdc++.h>
#define LL long long
#define MOD 998244353
int mul(const int &a, const int &b)
{
    return 1LL * a * b % MOD;
}
void Inc(int &a, const int &b)
{
    ((a += b) >= MOD) && (a -= MOD);
}
void Mul(int &a, const int &b)
{
    a = 1LL * a * b % MOD;
}
void Sqr(int &a)
{
    a = 1LL * a * a % MOD;
}
int qwqmi(int x, int k = MOD - 2)
{
    int res = 1;
    while(k)
    {
        if(k & 1) Mul(res, x);
        Sqr(x), k >>= 1;
    }
    return res;
}
using namespace std;
const int N = 5e3 + 5;
int two[N], fac[N], facinv[N];
void preprocess()
{
    two[0] = 1;
    for(int i = 1; i < N; ++i)
        two[i] = mul(two[i - 1], 2);
    fac[0] = facinv[0] = 1;
    for(int i = 1; i < N; ++i)
        fac[i] = mul(fac[i - 1], i);
    facinv[N - 1] = qwqmi(fac[N - 1]);
    for(int i = N - 2; i >= 1; --i)
        facinv[i] = mul(facinv[i + 1], i + 1);
}
int C(int n, int m)
{
    if(n < m) return 0;
    return mul(fac[n], mul(facinv[m], facinv[n - m]));
}
int n, m;
int p[N];
int sze[N], szv[N];
int bcnt;
int f[N][N];
int find(int x)
{
    if(x != p[x])
        p[x] = find(p[x]);
    return p[x];
}
void merge(int x, int y)
{
    x = find(x), y = find(y);
    if(x != y)
    {
        szv[x] += szv[y];
        sze[x] += sze[y];
        p[y] = x;
    }
    sze[x]++;
}
int main()
{
    preprocess();
    scanf("%d %d", &n, &m);
    for(int i = 1; i <= n; ++i)
    {
        p[i] = i;
        szv[i] = 1;
    }
    for(int i = 1; i <= m; ++i)
    {
        int a, b;
        scanf("%d %d", &a, &b);
        merge(a, b);
    }
    f[0][0] = 1;
    for(int i = 1; i <= n; ++i)
        if(p[i] == i)
        {
            ++bcnt;
            for(int j = 0; j <= n; ++j)
                for(int k = 0; k <= min(j, szv[i]); k += 2)
                    Inc(f[bcnt][j], mul(C(szv[i], k), mul(two[sze[i] - szv[i] + 1], f[bcnt - 1][j - k])));
        }
    for(int i = 0; i <= n; ++i)
        printf("%d\n", f[bcnt][i]);
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:75:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   75 |     scanf("%d %d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~
./Main.cpp:84:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   84 |         scanf("%d %d", &a, &b);
      |         ~~~~~^~~~~~~~~~~~~~~~~

Judge Result