poj3680 Intervals 【最小费用最大流+离散化】

#include<stdio.h>
#include<string.h>
#include<vector>
#include<queue>
#include<algorithm>
using namespace std;
const int N=5024;
const int inf=0x7fffffff;
struct Edge
{
int from,to,cap,flow,cost;
};
vector<Edge>edges;
vector<int>G
;
int inq
,p
,d
,a
;

void AddEdge(int from, int to,int cap, int cost)
{
Edge tp;
tp.from=from,tp.to=to,tp.cap=cap,tp.flow=0,tp.cost=cost;
edges.push_back(tp);

tp.from=to,tp.to=from,tp.cap=0,tp.flow=0,tp.cost=-cost;
edges.push_back(tp);

int g=edges.size();
G[from].push_back(g-2);
G[to].push_back(g-1);
}

int BellmanFord(int s,int t,int &flow, int &cost,int n)
{
int i,j,u;
for(i=0; i<=n+1; i++) d[i]=inf;
memset(inq,0,sizeof(inq));
d[s]=0;
inq[s]=1;
p[s]=0;
a[s]=inf;
queue<int>Q;
Q.push(s);
while(!Q.empty())
{
u=Q.front();
Q.pop();
inq[u]=0;
for(i=0; i<G[u].size(); i++)
{
Edge &e=edges[G[u][i]];
if(e.cap>e.flow&&d[e.to]>d[u]+e.cost)
{
d[e.to]=d[u]+e.cost;
p[e.to]=G[u][i];
a[e.to]=min(a[u],e.cap-e.flow);
if(!inq[e.to])
{
Q.push(e.to);
inq[e.to]=1;
}
}
}
}
if(d[t]==inf) return 0;
flow+=a[t];
cost+=d[t]*a[t];
u=t;
while(u!=0)
{
edges[p[u]].flow+=a[t];
edges[p[u]^1].flow-=a[t];
u=edges[p[u]].from;
}
return 1;
}

int Mincost(int s,int t,int n)
{
int flow=0,cost=0;
while(BellmanFord(s,t,flow,cost,n));
return cost;
}

void init(int n)
{
for(int i=0; i<=n+1; i++) G[i].clear();
edges.clear();
}

int main()
{
vector<int>x;
int s,t,_,i,u,v,c,n,m,k,a[1024],b[1024],w[1024];
scanf("%d",&_);
while(_--)
{
scanf("%d%d",&m,&k);
x.clear();
for(i=0;i<m;i++)
{
scanf("%d%d%d",&a[i],&b[i],&w[i]);
x.push_back(a[i]);
x.push_back(b[i]);
}
sort(x.begin(),x.end());
x.erase(unique(x.begin(),x.end()),x.end());
n=x.size();
s=n;t=s+1;
init(n+1);
for(int i=0;i+1<n;i++)
AddEdge(i,i+1,k,0);
AddEdge(s,0,k,0);
AddEdge(n-1,t,k,0);
n++;
for(i=0;i<m;i++)
{
a[i]=find(x.begin(),x.end(),a[i])-x.begin();
b[i]=find(x.begin(),x.end(),b[i])-x.begin();
AddEdge(a[i],b[i],1,-w[i]);
}
printf("%d\n",-Mincost(s,t,n));
}
return 0;
}