奖品分配(Prize Distribution) 题解

思路分析

按题目要求使用对应数据结构与算法模拟/递推求解，注意数据范围边界与时间复杂度。

参考代码

#include <iostream>
#include <vector>
using namespace std;

const int MOD = 1000000007;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    vector<vector<int>> C(1005, vector<int>(1005, 0));
    for (int i = 0; i <= 1002; ++i) {
        C[i][0] = 1;
        for (int j = 1; j <= i; ++j) {
            C[i][j] = (C[i - 1][j - 1] + C[i - 1][j]) % MOD;
        }
    }
    int T;
    if (!(cin >> T)) return 0;
    while (T--) {
        int n, m;
        cin >> n >> m;
        vector<int> a(m);
        int sum = 0;
        for (int i = 0; i < m; ++i) {
            cin >> a[i];
            sum += a[i];
        }
        long long ans = 1;
        int rem = sum;
        for (int i = 0; i < m; ++i) {
            ans = ans * C[rem][a[i]] % MOD;
            rem -= a[i];
        }
        cout << ans << "\n";
    }
    return 0;
}