[bzoj2697] 特技飞行

 1 #include<cstdio>
 2 #include<iostream>
 3 #include<cstring>
 4 #include<algorithm>
 5 #define ll long long
 6 using namespace std;
 7 const int maxn=303;
 8 int a[maxn];
 9 int i,j,k,n,m,ans;
10  
11 int ra;char rx;
12 inline int read(){
13     rx=getchar(),ra=0;
14     while(rx<‘0‘||rx>‘9‘)rx=getchar();
15     while(rx>=‘0‘&&rx<=‘9‘)ra*=10,ra+=rx-48,rx=getchar();return ra;
16 }
17 int main(){
18     n=read(),k=read();
19     for(i=1;i<=k;i++)a[i]=read();
20     sort(a+1,a+1+k);
21     int sz=n-1,top=k;
22     while(sz>0&&top>0)
23         ans+=sz*a[top],top--,sz-=2;
24     printf("%d\n",ans);
25 }
26