【哈弗曼树】HDU 5350 MZL's munhaff function

#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

typedef long long ll;

inline bool rd(int &ret) {
    char c; int sgn;
    if(c = getchar() , c == EOF) return false;
    while(c != ‘-‘ && (c < ‘0‘ || c > ‘9‘)) c = getchar();
    sgn = (c == ‘-‘) ? -1 : 1;
    ret = (c == ‘-‘) ? 0 : (c - ‘0‘);
    while(c = getchar(), c >= ‘0‘ && c <= ‘9‘) ret = ret * 10 + (c - ‘0‘);
    ret *= sgn;
    return true;
}

priority_queue<ll,vector<ll>, greater<ll> > q;

int main() {
    int T;
    scanf("%d", &T);
    while (T-- > 0) {
        int n; rd(n);
        while (!q.empty()) q.pop();
        for (int i = 0; i < n; ++i) {
            int x; rd(x);
            q.push(x);
        }
        ll ans = 0;
        while (!q.empty()) {
            ll x = q.top(); q.pop();
            if (q.empty()) break;
            ll y = q.top(); q.pop();
            ans += x + y;
            q.push(x + y);
        }
        printf("%I64d\n", ans);
    }
    return 0;
}