BZOJ 2563 阿狸和桃子的游戏

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define maxv 10050
using namespace std;
long long n,m,w[maxv],x,y,z;
int main()
{
scanf("%lld%lld",&n,&m);
for (long long i=1;i<=n;i++)
{
scanf("%lld",&w[i]);
w[i]*=2;
}
for (long long i=1;i<=m;i++)
{
scanf("%lld%lld%lld",&x,&y,&z);
w[x]+=z;w[y]+=z;
}
long long ans=0;
sort(w+1,w+n+1);
for (long long i=n;i>0;i-=2)
ans+=(w[i]-w[i-1]);
printf("%lld\n",ans/2);
return 0;
}