Submission #3246145

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define REP(i, n) for(int i = 0; i < n; i++)
#define REPR(i, n) for(int i = n; i >= 0; i--)
#define FOR(i, m, n) for(int i = m; i < n; i++)
#define FORR(i, m, n) for(int i = m; i >= n; i--)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define ll long long
#define pb(a) push_back(a)

ll dp[51][51][2501];

int main(){
  int n, a;
  cin >> n >> a;
  vector<int> x(n);
  REP(i, n) cin >> x[i];

  dp[0][0][0] = 1;

  REP(j, 50){
    REP(k, 50){
      REP(s, 2501 - x[j]){
        if(j >= 1 && s < x[j]) dp[j][k][s] = dp[j - 1][k][s];
        else if(j >= 1 && k >= 1 && s >= x[j]) dp[j][k][s] = dp[j - 1][k][s] + dp[j][k - 1][s - x[j]];
      }
    }
  }

  ll ans = 0;
  REP(i, n) ans += dp[n][i + 1][(i + 1) * a];

  cout << ans << endl;
}

Submission Info

Judge Result