Coin Combinations II

#include <bits/stdc++.h>

using namespace std;

const int N = 1e6 + 3;
const int mod = 1e9 + 7;

int n, x;
int dp[N], a[N];

int main(){
    cin >> n >> x;

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

    dp[0] = 1;

    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= x; j++) {
            if (j - a[i] >= 0) {
                dp[j] = (dp[j] + dp[j - a[i]]) % mod;
            }
        }
    }

    cout << dp[x] << endl;
}