题目：http://acm.hust.edu.cn/vjudge/contest/view.action?cid=26304#problem/C
这题实际上就是先从大到小排序，每次对前4^i 个数求和，i from 0 to n，再求总和，意思弄懂就很水了
#include<cstdio> #include<algorithm> #include<cmath> using namespace std; long long arr[2000001]; bool cmp(int a, int b) { return a > b; } int main() { freopen("7.16C.txt", "r", stdin); int N; while(scanf("%d", &N) != EOF) { for(int i = 0; i < N; ++ i) { scanf("%I64d", &arr[i]); } sort(arr, arr + N, cmp); long long sum = 0; int total = N; while(total) { for(int i = 0; i < total; ++ i) { sum += arr[i]; } total /= 4; } printf("%I64d\n", sum); } return 0; } |