Go: // Warshall–Floyd Algorithm

package main

import (
	"bufio"
	"os"
	"strings"
	"strconv"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

const INF = 0x7FFFFFFF

func main() {
	for scanner.Scan() {
		buf := strings.Split(scanner.Text(), " ")
		n, _ := strconv.Atoi(buf[0])
		m, _ := strconv.Atoi(buf[1])
		if n == 0 && m == 0 {
			break
		}
		c_matrix := make([][]int, m)
		for i := range c_matrix {
			c_matrix[i] = make([]int, m)
		}
		t_matrix := make([][]int, m)
		for i := range t_matrix {
			t_matrix[i] = make([]int, m)
		}
		for i := 0; i < n; i++ {
			scanner.Scan()
			buf_ := strings.Split(scanner.Text(), " ")
			a, _ := strconv.Atoi(buf_[0])
			b, _ := strconv.Atoi(buf_[1])
			c, _ := strconv.Atoi(buf_[2])
			t, _ := strconv.Atoi(buf_[3])
			c_matrix[a-1][b-1] = c
			t_matrix[a-1][b-1] = t
		}
		c_dist := make([][]int, m)
		c_prev := make([][]int, m)
		t_dist := make([][]int, m)
		t_prev := make([][]int, m)
		for i := 0; i < m; i++ {
			c_dist[i] = make([]int, m)
			c_prev[i] = make([]int, m)
			t_dist[i] = make([]int, m)
			t_prev[i] = make([]int, m)
		}
		for i := 0; i < m; i++ {
			for j := 0; j < m; j++ {
				if c_matrix[i][j] == 0{
					c_dist[i][j] = INF
				} else {
					c_dist[i][j] = c_matrix[i][j]
				}
				if c_matrix[i][j] == 0{
					c_prev[i][j] = -1
				} else {
					c_prev[i][j] = i
				}
				if t_matrix[i][j] == 0{
					t_dist[i][j] = INF
				} else {
					t_dist[i][j] = t_matrix[i][j]
				}
				if t_matrix[i][j] == 0{
					t_prev[i][j] = -1
				} else {
					t_prev[i][j] = i
				}
			}
			c_dist[i][i] = 0
			t_dist[i][i] = 0
		}
		for k := 0; k < m; k++ {
			for i := 0; i < m; i++ {
				for j := 0; j < m; j++ {
					c_newlen := c_dist[i][k] + c_dist[k][j]
					if c_newlen < c_dist[i][j] {
						c_dist[i][j] = c_newlen
						c_prev[i][j] = c_prev[k][j]
					}
				}
			}
		}
		for k := 0; k < m; k++ {
			for i := 0; i < m; i++ {
				for j := 0; j < m; j++ {
					t_newlen := t_dist[i][k] + t_dist[k][j]
					if t_newlen < t_dist[i][j] {
						t_dist[i][j] = t_newlen
						t_prev[i][j] = t_prev[k][j]
					}

				}
			}
		}
		scanner.Scan()
		k, _ := strconv.Atoi(scanner.Text())
		for i := 0; i < k; i++ {
			scanner.Scan()
			buf_ := strings.Split(scanner.Text(), " ")
			p, _ := strconv.Atoi(buf_[0])
			q, _ := strconv.Atoi(buf_[1])
			r, _ := strconv.Atoi(buf_[2])
			switch r {
			case 0: fmt.Println(c_dist[p-1][q-1])
			case 1: fmt.Println(t_dist[p-1][q-1])
			}
		}
	}
}

C++: #include<cstdio>
#include<climits>

using namespace std;

int a,b,c,d,T,n;
int s=0,min=INT_MAX,m,tul[102][102],yv[102][102]={0},tsag[102][102]={0};

int go(int x){
	if(x==b){
		if(s<min) min=s;
		return 0;
	}
	for(int i=1 ; i<=m ; i++ ){
		if(tul[x][i]!=0 && yv[x][i]==0){
			yv[x][i]=1;
			yv[i][x]=1;
			s+=tul[x][i];
			go(i);
			s-=tul[x][i];
			yv[x][i]=0;
			yv[i][x]=0;
		}
	}
}
int go1(int x){
	if(x==b){
		if(s<min) min=s;
		return 0;
	}
	for(int i=1 ; i<=m ; i++ ){
		if(tsag[x][i]!=0 && yv[x][i]==0){
			yv[x][i]=1;
			yv[i][x]=1;
			s+=tsag[x][i];
			go1(i);
			s-=tsag[x][i];
			yv[x][i]=0;
			yv[i][x]=0;
		}
	}
}

int main(){
	scanf("%d %d",&n,&m);
	for(int i=0 ; i<n ; i++ ){
		scanf("%d %d %d %d",&a,&b,&c,&d);
		tul[a][b]=c;
		tul[b][a]=c;
		tsag[a][b]=d;
		tsag[b][a]=d;
	}
	scanf("%d",&T);
	while(T--){
		scanf("%d %d %d",&a,&b,&c);
		s=0;
		min=INT_MAX;
		d=1;
		if(c==0) go(a);
		else go1(a);
		printf("%d\n",min);
	}
}

C++: #include<iostream>
#include<vector>
#include<queue>
#include<map>
#define pb push_back
#define INF 1000000000
using namespace std;
typedef pair<int,int> P;
int n;

struct edge{
	int to,cost;
	edge(int to,int cost):to(to),cost(cost){}
};
vector<vector<edge> > G1,G2;


int dijkstra1(int s,int t){
	priority_queue<P,vector<P> , greater<P> > que;
	vector<int> d(n,INF);
	d[s]=0;
	que.push(P(0,s));
	while(!que.empty()){
		P q=que.top();
		que.pop();
		int now=q.second,dist=q.first;
		if(now==t){
			return dist;
		}
		
		if(d[now]<dist)
			continue;
		
		for(int i=0;i<(int)G1[now].size();i++){
			if(G1[now][i].cost+dist<d[G1[now][i].to]){
				que.push(P(G1[now][i].cost+dist,G1[now][i].to));
				d[G1[now][i].to]=G1[now][i].cost+dist;
			}
		}
	}
	return -1;
	
}
int dijkstra2(int s,int t){
	priority_queue<P,vector<P> , greater<P> > que;
	vector<int> d(n,INF);
	d[s]=0;
	que.push(P(0,s));
	while(!que.empty()){
		P q=que.top();
		que.pop();
		int now=q.second,dist=q.first;
		if(now==t){
			return dist;
		}
		
		if(d[now]<dist)
			continue;
		
		for(int i=0;i<(int)G2[now].size();i++){
			if(G2[now][i].cost+dist<d[G2[now][i].to]){
				que.push(P(G2[now][i].cost+dist,G2[now][i].to));
				d[G2[now][i].to]=G2[now][i].cost+dist;
			}
		}
	}
	return -1;
}
int main(){
	int m;
	while(cin>>m>>n,n||m){
		G1.resize(n);
		G2.resize(n);
		G1.clear();
		G2.clear();
		for(int i=0;i<m;i++){
			int a,b,c,t;
			cin>>a>>b>>c>>t;a--;b--;
			G1[a].pb(edge(b,c));
			G1[b].pb(edge(a,c));
			G2[a].pb(edge(b,t));
			G2[b].pb(edge(a,t));
		}

		
		int k;
		cin>>k;
		for(int i=0;i<k;i++){
			int p,q,r;
			cin>>p>>q>>r;p--,q--;
			if(r==0){
				cout<<dijkstra1(p,q)<<endl;
			}else
				cout<<dijkstra2(p,q)<<endl;
			
			
		}
		
	}
	
	return 0;
}

C++: #include <iostream>
#include <cstring>
using namespace std;

const int INF = 1000000;
const int MAX_V = 101;

int cost[MAX_V][MAX_V];
int time[MAX_V][MAX_V];
int d[MAX_V];
bool used[MAX_V];
int V;

int n,m;

void dijkstra(int s,bool r){
    fill(d,d+m,INF);
    memset(used,false,sizeof(used));
    d[s]=0;
    while(1){
        int v=-1;
        for(int u=0;u<m;u++){
            if(used[u]) continue;
            if(v==-1||d[u]<d[v]){
                v=u;
            }
        }
        if(v==-1) break;
        used[v]=true;
        for(int u=0;u<m;u++){
            int c;
            if(r) c=cost[u][v];
            else c=time[u][v];
            d[u]=min(d[u],d[v]+c);
        }
    }
}
int main(){
    while(cin >> n >> m,n+m){
        for(int i=0;i<m+1; i++){
            for(int j=0; j<m; j++){
                cost[i][j]=INF;
                time[i][j]=INF;
            }
        }
        for (int i = 0; i < m+1; ++i) {
            cost[i][i]=0;
            time[i][i]=0;
        }
        for (int i = 0; i < n; ++i) {
            int to,from,c,t;
            cin >> to>>from>>c>>t;
            to--; from--;
            cost[to][from]=c;
            cost[from][to]=c;
            time[to][from]=t;
            time[from][to]=t;
        }
        int k; cin>>k;
        for (int i = 0; i < k; ++i) {
            int p,q,r;
            cin>>p>>q>>r;
            p--; q--;
            dijkstra(p,!r);
            cout<<d[q]<<endl;
        }
    }
}