Go: // Warshall–Floyd Algorithm

package main

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

var scanner = bufio.NewScanner(os.Stdin)

const INF = 2000000000

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
					c_prev[i][j] = -1
				} else {
					c_dist[i][j] = c_matrix[i][j]
					c_prev[i][j] = i
				}
				if t_matrix[i][j] == 0 {
					t_dist[i][j] = INF
					t_prev[i][j] = -1
				} else {
					t_dist[i][j] = t_matrix[i][j]
					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<string>
#include<vector>
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<sstream>
#include<functional>
#include<map>
#include<set>
#include<cmath>

#define REP(i,s,e) for(int i=int(s);i<=int(e);i++)
#define rep(i,n) for(int i=0;i<int(n);i++)

using namespace std;

#define INF 10000

int m,x,y;
int c[101][101],ct[101][101];
int d[101],dt[101];
bool b[101],bt[101];

void mc(int s){
rep(i,101){
d[i]=INF; b[i]=false;
}
d[s]=0;

while(1){
int M=INF;
rep(i,m){
if(!b[i] && d[i]<M){
	M=d[i]; x=i;
}
}

if(M==INF) break;

b[x]=true;
rep(i,m) d[i]=min(d[i],d[x]+c[x][i]);

}
}

void mt(int s){
rep(i,101){
dt[i]=INF; bt[i]=false;
}
dt[s]=0;

while(1){
int M=INF;
rep(i,m){
if(!bt[i] && dt[i]<M){
	M=dt[i]; y=i;
}
}

if(M==INF) break;

bt[y]=true;
rep(i,m) dt[i]=min(dt[i],dt[y]+ct[y][i]);

}
}

int main(){

int n,a,b,cs,tm,k,p,q,r;

while(1){
	
rep(i,101){
rep(j,101){
	c[i][j]=INF;
    ct[i][j]=INF;
}
}	
	
cin >> n >> m;
if(n==0 && m==0) break;

rep(i,n){
cin >> a >> b >> cs >> tm;

c[a-1][b-1]=cs; c[b-1][a-1]=cs;
ct[a-1][b-1]=tm; ct[b-1][a-1]=tm;
}

cin >> k;

rep(i,k){
cin >> p >> q >> r;

if(r==0){
	mc(p-1); cout << d[q-1] << endl;

}

else{
	mt(p-1); cout << dt[q-1] << endl;

}
}

}

	return 0;
}

C++: #include<cstdio>
#include<vector>
#include<algorithm>

#define rep(i,n) for(int i=0;i<(n);i++)

using namespace std;

template<class T>
class d_heap_for_Dijkstra{
	static const int N_MAX=100;
	int n,d,key[N_MAX],pos[N_MAX];
	T val[N_MAX];

	void sift_up(int i,const T &x){
		val[i]=x;
		while(i!=0 && val[(i-1)/d]>val[i]){
			int p=(i-1)/d;
			swap(pos[key[p]],pos[key[i]]);
			swap(key[p],key[i]);
			swap(val[p],val[i]);
			i=p;
		}
	}
	void sift_down(int i,const T &x){
		val[i]=x;
		for(int j,k,c;;i=j){
			j=i;
			for(c=0,k=d*i+1;c<d;c++,k++) if(k<n && val[j]>val[k]) j=k;
			if(j==i) break;
			swap(pos[key[j]],pos[key[i]]);
			swap(key[j],key[i]);
			swap(val[j],val[i]);
		}
	}
public:
	d_heap_for_Dijkstra(int d):n(0),d(d){}
	int find_min()const{ return key[0]; }
	void insert(int u,const T &x){
		int i=n++;
		key[i]=u;
		pos[u]=i;
		sift_up(i,x);
	}
	void delete_min(){
		n--;
		pos[key[n]]=pos[key[0]];
		key[0]=key[n];
		sift_down(0,val[n]);
	}
	void decrease_key(int u,const T &x){
		sift_up(pos[u],x);
	}
	bool empty()const{ return n==0; }
	int size()const{ return n; }
};

const int INF=1<<29;

struct edge{ int v,cost1,cost2; };

int main(){
	for(int m,n;scanf("%d%d",&m,&n),n;){
		vector<edge> G[100];
		rep(i,m){
			int u,v,cost1,cost2; scanf("%d%d%d%d",&u,&v,&cost1,&cost2); u--; v--;
			G[u].push_back((edge){v,cost1,cost2});
			G[v].push_back((edge){u,cost1,cost2});
		}

		int q; scanf("%d",&q);
		while(q--){
			int s,t,type; scanf("%d%d%d",&s,&t,&type); s--; t--;

			int d[100];
			rep(u,n) d[u]=(u==s?0:INF);
			d_heap_for_Dijkstra<int> H(5);
			H.insert(s,0);
			while(!H.empty()){
				int u=H.find_min();
				H.delete_min();

				rep(i,G[u].size()){
					const edge &e=G[u][i];
					int d2=d[u]+(type==0?e.cost1:e.cost2);
					if(d[e.v]>d2){
						if(d[e.v]==INF) H.insert(e.v,d2);
						else            H.decrease_key(e.v,d2);
						d[e.v]=d2;
					}
				}
			}

			printf("%d\n",d[t]);
		}
	}

	return 0;
}

C++: #include <array>
#include <iostream>
using namespace std;
 
array<array<int, 210>, 210> costs;
array<array<int, 210>, 210> times;
 
int main() {
    int n, m;
    while (cin >> n >> m, n || m) {
        for (auto& ar : costs) ar.fill(1000000);
        for (auto& ar : times) ar.fill(1000000);
        for (int i = 0; i < n; i++) {
            int a, b, c, t; cin >> a >> b >> c >> t;
            a--; b--;
            costs[a][b] = costs[b][a] = c;
            times[a][b] = times[b][a] = t;
        }
        for (int i = 0; i < m; i++) {
            costs[i][i] = 0;
            times[i][i] = 0;
        }
 
        for (int k = 0; k < m; k++) {
            for (int i = 0; i < m; i++) {
                for (int j = 0; j < m; j++) {
                    costs[i][j] = min(costs[i][j], costs[i][k] + costs[k][j]);
                    times[i][j] = min(times[j][k], times[i][k] + times[k][j]);
                }
            }
        }
        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 << costs[p][q] << endl;
            }
            else {
                cout << times[p][q] << endl;
            }
        }
    }
}