挺简单的一道题目，设 $f_i$ 表示 $i$ 能被多少种组合表示出来，那么显然有 $f_i = \max(f_i, f_{i-a_j} + 1)$。

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

const int MAXN = 105, MAXL = 25005;
int T, n, a[MAXN], f[MAXL];

int main(void) {
    ios::sync_with_stdio(false);
    cin >> T;
    while (T--) {
        cin >> n; int ans = 0;
        for (int i = 1; i <= n; ++i) cin >> a[i];
        memset(f, 0xcf, sizeof f);
        f[0] = 0;
        for (int i = 1; i <= n; ++i) {
            for (int j = a[i]; j <= MAXL; ++j) {
                f[j] = max(f[j], f[j - a[i]] + 1);
            }
        }
        for (int i = 1; i <= n; ++i) if (f[a[i]] == 1) ++ans;
        cout << ans << endl;
    }
    return 0;
}