问题描述：

---

题解：

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 105;
const ll p = 1e6 + 7;
ll a[N], dp[N][N];


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

  dp[0][0] = 1;

  for(int i = 1; i <= n; i++)
  {
    for(int j = 0; j <= m; j++)
    {
      for(int k = 0; k <= a[i] && k <= j; k++)
      dp[i][j] = (dp[i][j] + dp[i - 1][j - k]) % p;  // k表示个数
    }
  }  
  cout << dp[n][m] << '\n';
  return 0;
}