1636 - Coin Combinations II.cpp

#include <bits/stdc++.h>
using namespace std;

int main() {
   int mod = 1e9 + 7;
   int n, target;
   cin >> n >> target;
   vector<int> x(n);
   for (int& v : x) cin >> v;

   vector<vector<int>> dp(n + 1, vector<int>(target + 1, 0));
   dp[0][0] = 1;
   for (int i = 1; i <= n; i++) {
      for (int j = 0; j <= target; j++) {
         dp[i][j] = dp[i - 1][j];
         int left = j - x[i - 1];
         if (left >= 0) {
            (dp[i][j] += dp[i][left]) %= mod;
         }
      }
   }
   cout << dp[n][target] << endl;
}