Codeforces 439B Devu, the Dumb Guy

题目链接：Codeforces 439B Devu, the Dumb Guy

排序，先学章节少的。

#include <iostream>#include <cstdio>#include <algorithm>using namespace std;const int MAX_N = 100000 + 100;int arr[MAX_N];int main(){    int n, k;    scanf("%d%d", &n, &k);    for(int i = 0; i < n; i++)        scanf("%d", &arr[i]);    sort(arr, arr + n);    __int64 now = k, cost = 0;    for(int i = 0; i < n; i++)    {        if(now < 1)            now = 1;        cost += now * arr[i];        now--;    }    printf("%I64d\n", cost);    return 0;}