CodeForces-462C Appleman and Toastman

#include <iostream>#include <algorithm>#include <cstdio>using namespace std;const int maxn = 3e5 + 5;long long num[maxn];long long sum, ans;int n;int main(){    while(~scanf("%d", & n))    {        sum = 0;        for(int i = 0; i < n; i ++)            scanf("%I64d", & num[i]);        sort(num, num + n);        for(int i = 0; i < n; i ++)            sum += num[i];        ans = sum;        for(int i = 0; i < n - 1; i ++)        {            ans += sum;            sum -= num[i];        }        printf("%I64d\n", ans);    }    return 0;}

题意：输入n。算总和先。之后每次去一个数（要加在总和） 继续加在总和中。直到最后只有2个元素。

题解：水题。随意玩。ans记得用long long..cin 和 scanf 输入时间差很多..