transaction transaction transaction 最大费用最大流转化到SPFA最长路

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<sstream>
#include<algorithm>
#include<queue>
#include<deque>
#include<iomanip>
#include<vector>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#include<functional>
#include<fstream>
#include<memory>
#include<list>
#include<string>
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;

//最大费用最大流 简化到SPFA上特例
const int MAXN = 100000 + 65;
struct edge
{
    int to, next, cost;
}E[MAXN << 2];
int head[MAXN], tot, n;
int val[MAXN];
bool vis[MAXN];
int lowcost[MAXN];
void init()
{
    memset(head, -1, sizeof(head));
    tot = 0;
}
void addedge(int u, int v, int d)
{
    E[tot].to = v;
    E[tot].cost = d;
    E[tot].next = head[u];
    head[u] = tot++;
}
int spfa(int st, int ed)
{
    memset(vis, false, sizeof(vis));
    memset(lowcost, 0, sizeof(lowcost));
    queue<int> q;
    q.push(st);
    vis[st] = true;
    lowcost[st] = 0;
    while (!q.empty())
    {
        int f = q.front();
        q.pop();
        vis[f] = false;
        for (int i = head[f]; i != -1; i = E[i].next)
        {
            int v = E[i].to, d = E[i].cost;
            if (lowcost[v] < lowcost[f] + d)
            {
                lowcost[v] = lowcost[f] + d;
                if (!vis[v])
                {
                    vis[v] = true;
                    q.push(v);
                }
            }
        }
    }
    return lowcost[ed];
}
int main()
{
    int T;
    scanf("%d", &T);
    while (T--)
    {
        init();
        scanf("%d", &n);
        for (int i = 1; i <= n; i++)
        {
            scanf("%d", &val[i]);
            addedge(0, i, val[i]);
            addedge(i, n + 1, -val[i]);
        }
        int u, v, d;
        for (int i = 0; i < n - 1; i++)
        {
            scanf("%d%d%d", &u, &v, &d);
            addedge(u, v, -d);
            addedge(v, u, -d);
        }
        printf("%d\n", spfa(0, n + 1));
    }
}