poj 3680(最大费用最大流)

构图参考：http://www.cppblog.com/abilitytao/archive/2010/03/30/111042.html

// File Name: 3680.cpp
// Author: Missa
// Created Time: 2013/4/19 星期五 15:57:48

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<queue>
#include<stack>
#include<string>
#include<vector>
#include<cstdlib>
#include<map>
#include<set>
using namespace std;
#define CL(x,v) memset(x,v,sizeof(x));
#define R(i,st,en) for(int i=st;i<en;++i)
#define LL long long

const int maxn = 450;
const int maxm = 450 * 450;
const int inf = 0x3f3f3f3f;
struct Edge
{
    int v, cap, cost, next;
}p[maxm << 1];
int e, sumFlow, n, m, st, en;
int head[maxn], dis[maxn], pre[maxn];
bool vis[maxn];
void init()
{
    e=0;
    memset(head,-1,sizeof(head));
}
void addEdge(int u,int v,int cap,int cost)
{
    p[e].v = v; p[e].cap = cap; p[e].cost = cost;
    p[e].next = head[u]; head[u] = e++;
    p[e].v = u; p[e].cap = 0; p[e].cost = - cost;
    p[e].next = head[v]; head[v] = e++;
}
bool spfa(int s,int t, int n)
{
    int u,v;
    queue<int>q;
    memset(vis,false,sizeof(vis));
    memset(pre,-1,sizeof(pre));
    for(int i = 0; i <= n; ++i) 
        dis[i] = inf;
    vis[s] = true;
    dis[s] = 0;
    q.push(s);
    while(!q.empty())
    {
        u = q.front();
        q.pop();
        vis[u] = false;
        for(int i = head[u]; i != -1; i = p[i].next)
        {
            v = p[i].v;
            if(p[i].cap && dis[v] > dis[u] + p[i].cost)
            {
                dis[v] = dis[u] + p[i].cost;
                pre[v] = i;
                if(!vis[v])
                {
                    q.push(v);
                    vis[v]=true;
                }
            }
        }
     }
     if(dis[t] == inf) 
         return false;
     return true;
}
int MCMF(int s,int t,int n)
{
    int flow = 0; // 总流量
    int minflow, mincost;
    mincost=0;
    while(spfa(s,t,n))
    {
        minflow = inf + 1;
        for(int i = pre[t]; i != -1; i = pre[p[i^1].v])
            if(p[i].cap < minflow)
                minflow = p[i].cap;
        flow += minflow;
        for(int i=pre[t];i!=-1;i=pre[p[i^1].v])
        {
            p[i].cap -= minflow;
            p[i^1].cap += minflow;
        }
        mincost += dis[t] * minflow;
    }
    sumFlow = flow; // 最大流
    return mincost;
}
int N, K;
struct Node
{
    int u, v, c;
}ed[maxn];
int pos[100005];
vector<int>v;
int main()
{
    int test;
    scanf("%d",&test);
    while (test--)
    {
        init();
        n = 1;
        memset(pos, 0, sizeof(pos));
        scanf("%d%d", &N, &K);
        v.clear();
        for (int i = 0; i < N; ++i)
        {
            scanf("%d%d%d",&ed[i].u, &ed[i].v, &ed[i].c);
            v.push_back(ed[i].u);
            v.push_back(ed[i].v);
        }
        sort(v.begin(),v.end());
        for (int i = 0; i < v.size(); ++i)
            if (pos[v[i]] == 0)
                pos[v[i]] = n ++;
        st = 0, en = n;
        for (int i = 0; i < n; ++i)
            addEdge(i, i + 1, K, 0);
        for (int i = 0; i < N; ++i)
            addEdge(pos[ed[i].u], pos[ed[i].v], 1, -ed[i].c);
        printf("%d\n",-MCMF(st, en, n));
    }
    return 0;
}