P4643 [国家集训队]阿狸和桃子的游戏

题面

https://www.luogu.org/problem/P4643

题解

#include<cstdio>
#include<iostream>
#include<algorithm>
using namespace std;
int n,m,a[10500];
bool cmp(int x,int y){
  return x>y;
}
int main(){
  int i,u,v,w;
  scanf("%d %d",&n,&m);
  for (i=1;i<=n;i++) {
    scanf("%d",&a[i]);
    a[i]<<=1;
  }
  for (i=1;i<=m;i++) {
    scanf("%d %d %d",&u,&v,&w);
    a[u]+=w; a[v]+=w;
  }
  sort(a+1,a+n+1,cmp);
  int tz=0,al=0;
  for (i=1;i<=n>>1;i++) {
    tz+=a[2*i-1];
    al+=a[2*i];
  }
  cout<<((tz-al)>>1);
}