poj 1062 最短路

//
//  main.cpp
//  poj1062
//
//  Created by Fangpin on 15/6/10.
//  Copyright (c) 2015年 FangPin. All rights reserved.
//

#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
const int inf=0x6f6f6f6f;
using namespace std;
struct Edge{
int from,to,dist;
};
vector<Edge> edge1,edge2;
struct Data{
int price,level;
};
vector<Data> data;
int d[500],low,high,n;

int bf(){
for(int i=0;i<n;++i){
bool flag=false;
for(int j=0;j<edge2.size();++j){
Edge &e=edge2[j];
if(d[e.to]>d[e.from]+e.dist){
d[e.to]=d[e.from]+e.dist;
flag=true;
}
}
if(!flag) break;
}
int ans=inf;
for(int i=0;i<n;++i){
//        cout<<i<<" "<<d[i]<<" "<<d[i]+data[i].price<<endl;
ans=min(ans,d[i]+data[i].price);
}
//        ans=min(ans,d[i]);
return ans;
}

int main(int argc, const char * argv[]) {
int m;
while(~scanf("%d%d",&m,&n)){
data.clear();
edge1.clear();
edge2.clear();
int king_level;
for(int i=0;i<n;++i){
Data tem;
int x;
scanf("%d%d%d",&tem.price,&tem.level,&x);
if(!i) king_level=tem.level;
data.push_back(tem);
while(x--){
int to,dist;
scanf("%d%d",&to,&dist);
Edge e;
e.from=i;e.to=to-1;e.dist=dist;
edge1.push_back(e);
}
}
low=king_level;high=low+m;
int ans=inf;
//        edge2=edge1;
//        for(int i=0;i<edge2.size();++i)
//            cout<<"edge "<<edge2[i].from<<" "<<edge2[i].to<<" "<<edge2[i].dist<<endl;
//        memset(d,inf,sizeof(d));
//        d[0]=0;
//        ans=min(ans,bf());
while(high>=king_level){
edge2.clear();
memset(d,inf,sizeof(d));
d[0]=0;
for(int i=0;i<edge1.size();++i){
const Edge &e=edge1[i];
int x=data[e.from].level,y=data[e.to].level;
if(x>=low && x<=high && y>=low && y<=high){
edge2.push_back(e);
}
}
ans=min(ans,bf());
--low;
--high;
}
cout<<ans<<endl;
}
return 0;
}