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<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=1;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<string>
#include<vector>
#include<cstdio>
using namespace std;
const int INF = 1 << 20;

int main()
{
	bool jud[128];
	int rail, stat, cost[128][128], time[128][128], start, goal, kind, route[128], exp[128], num;
	int wk, tk, kt, kr;
	while(cin >> rail >> stat)
	{
		if(!rail && !stat) break;
		for(int i = 0; i < stat; i++)
		{
			for(int j = 0; j < stat; j++)
			{
				cost[i][j] = INF;
				cost[i][j] = INF;
			}
		}

		for(int i = 0; i < rail; i++)
		{
			cin >> wk >> tk >> kt >> kr;
			cost[wk-1][tk-1] = kt;
			cost[tk-1][wk-1] = kt;
			time[wk-1][tk-1] = kr;
			time[tk-1][wk-1] = kr;
		}
		/*
		for(int i = 0; i < rail; i++)
		{
			for(int j = 0; j < rail; j++)
			{
				printf("%3d ",cost[i][j]);
			}
			puts("");
		}
		*/

		cin >> num;

		for(int m = 0; m < num; m++)
		{
			for(int i = 0; i < stat; i++)
			{
				jud[i] = false;
				route[i] = INF;
				exp[i] = INF;
		
			}

			cin >> start >> goal >> kind;
			route[start - 1] = 0;
			while(1)
			{	
				int v = -1;
				for(int u = 0; u < stat; u++)
				{
					if(!jud[u] && (v == -1 || route[u] < route[v]) ) v = u;
				}

				if(v == -1) break;

				jud[v] = true;

				for(int u = 0; u < stat; u++)
				{
					route[u] = min(route[u], route[v] + cost[v][u]);
				}
				//puts("run");
				/*
				for(int u = 0; u < stat; u++)
				{
					printf("%15d %15d \n", route[u], jud[u] ); 
				}
				puts("");
				*/
			}

			cout << route[goal - 1] << endl;
		}
	}
}