pku3253 Fence Repair

 利用构建赫夫曼树的贪心思想来维护一个小顶堆

 

#include <iostream>#include <queue>using namespace std;int N;int woods[20001];int main(){int i, j;while (cin >> N){for (i=0; i<N; i++)cin >> woods[i];priority_queue<int, vector<int>, greater<int> > q(woods, woods+N);unsigned int sum = 0;while (q.size() >= 2){i = q.top();q.pop();j = q.top();q.pop();sum += i+j;q.push(i+j);}q.pop();cout << sum << endl;}}