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<stdio.h>
#include<stdlib.h>
#include<iostream>
#include<string.h>
#include<math.h>
#include<cstring>
using namespace std;
int mini(int a,int b){
	if(a<b){
		return a;
	}else{
		return b;
	}
}

int cost(int p,int q,int n,int co[][100]){
	int i,s[100],a,j,min,d[100],b;
	for(i=1;i<=n;i++){s[i]=0;d[i]=2000;}
	a=p;s[a]=1;min=1500;d[a]=0;
	for(i=1;i<=n;i++){
		for(j=1;j<=n;j++){
			d[j]= mini(d[j],d[a]+co[a][j]);
		}
		s[a]=1;b=2000;
		for(j=1;j<=n;j++){
			if(s[j]==0&&d[j]<b){
				a=j;b=d[j];
			}
		}
		s[a]=1;
	}
	return d[q];
}

int main(){
	while(1){
		int i,a=0,b=0,p,q,r,j,k,n,m,co[100][100],ti[100][100],s[100];
		for(i=0;i<100;i++){
			s[i]=0;
			for(j=0;j<100;j++){
				if(i==j){
					co[i][j]=0;
					ti[i][j]=0;
				}else{
					co[i][j]=2000;
					ti[i][j]=2000;
				}
			}
		}
		cin>>n>>m;
		if(n==0&&m==0)break;
		for(i=0;i<n;i++){
			cin>>a>>b;
			cin>>co[a][b]>>ti[a][b];
			co[b][a]=co[a][b];
			ti[b][a]=ti[a][b];
		}
		cin>>k;
		for(i=0;i<k;i++){
			cin>>p>>q>>r;
			if(r==0){
				cout<<cost(p,q,m,co)<<endl;
			}else{
				cout<<cost(p,q,m,ti)<<endl;
			}
		}
	}
    return 0;
}

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

const int INF = 2000;

struct LineTable{
  int cost;
  int times;
  LineTable(){
    cost = INF;
    times = INF;
  }
};

int main(){

    int n,m;
    while(1){
      cin >> n >> m;
      if(n==0&&m==0){
        break;
      }
      LineTable table[m][m];

      for(int i=0;i<m;i++){
        table[i][i].cost = 0;
        table[i][i].times = 0;
      }

      for(int i=0;i<n;i++){
        int a,b,cost,times;
        cin >> a >> b >> cost >> times;
        table[a-1][b-1].cost = cost;
        table[a-1][b-1].times = times;
        table[b-1][a-1].cost = cost;
        table[b-1][a-1].times = times;
      }

      for(int k=0;k<m;k++){
        for(int i=0;i<m;i++){
          for(int j=0;j<m;j++){
            if(table[i][j].cost > table[i][k].cost + table[k][j].cost){
              table[i][j].cost = table[i][k].cost + table[k][j].cost;
            }
          }
        }
      }

      for(int k=0;k<m;k++){
        for(int i=0;i<m;i++){
          for(int j=0;j<m;j++){
            if(table[i][j].times > table[i][k].times + table[k][j].times){
              table[i][j].times = table[i][k].times + table[k][j].times;
            }
          }
        }
      }

      for(int k=0;k<m;k++){
        for(int i=0;i<m;i++){
          for(int j=0;j<m;j++){
            if(table[j][i].cost > table[j][k].cost + table[k][i].cost){
              table[j][i].cost = table[j][k].cost + table[k][i].cost;
            }
          }
        }
      }

      for(int k=0;k<m;k++){
        for(int i=0;i<m;i++){
          for(int j=0;j<m;j++){
            if(table[j][i].times > table[j][k].times + table[k][i].times){
              table[j][i].times = table[j][k].times + table[k][i].times;
            }
          }
        }
      }

      for(int k=m-1;k>=0;k--){
        for(int i=m-1;i>=0;i--){
          for(int j=m-1;j>=0;j--){
            if(table[i][j].cost > table[i][k].cost + table[k][j].cost){
              table[i][j].cost = table[i][k].cost + table[k][j].cost;
            }
          }
        }
      }

      for(int k=m-1;k>=0;k--){
        for(int i=m-1;i>=0;i--){
          for(int j=m-1;j>=0;j--){
            if(table[i][j].times > table[i][k].times + table[k][j].times){
              table[i][j].times = table[i][k].times + table[k][j].times;
            }
          }
        }
      }

      int k,p,q,r;
      cin >> k;
      cin >> p >> q >> r;
      if(r==0){
        cout << table[p-1][q-1].cost;
      }
      else{
        cout << table[p-1][q-1].times;
      }
      for(int i=0;i<k;i++){
        cin >> p >> q >> r;
        if(r==0){
          cout << ' ' <<table[p-1][q-1].cost;
        }
        else{
          cout << ' ' <<table[p-1][q-1].times;
        }
      }
      cout << endl;
      /*
      for(int i=0;i<k;i++){
        cin >> p >> q >> r;
        if(r==0){
          cout << table[p-1][q-1].cost << endl;;
        }
        else{
          cout << table[p-1][q-1].times << endl;
        }
      }*/
    }
    return 0;
}

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

int main(){
  int n,m,a,b,cost,time,k,p,q,r;
  int t[100][100],c[100][100];

  for(;;){
    cin >> n >> m;
    if(!n && !m)break;

    for(int i=0;i<m;i++){
      for(int j=0;j<m;j++){
	if(i==j){
	  t[i][j] = 0;
	  c[i][j] = 0;
	}else{
	  t[i][j] = 1000000;
	  c[i][j] = 1000000;
	}
      }
    }

    for(int i=0;i<n;i++){
      cin >> a >> b >> cost >> time;
      t[a-1][b-1] = time;
      t[b-1][a-1] = time;
      c[a-1][b-1] = cost;
      c[b-1][a-1] = cost;
    }

    for(int x=0;x<m;x++){
      for(int i=0;i<m;i++){
	for(int j=0;j<m;j++){
	  t[i][j] = min(t[i][j],t[i][x] + t[x][j]);
	  c[i][j] = min(c[i][j],c[i][x] + c[x][j]);
	}
      }
    }

    cin >> k;
    for(int i=0;i<k;i++){
      cin >> p >> q >> r;
      if(r)cout << t[p-1][q-1] << endl;
      else cout << c[p-1][q-1] << endl;
    }
  }
}