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
			c_matrix[b-1][a-1] = c
			t_matrix[a-1][b-1] = t
			t_matrix[b-1][a-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=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;
      
     
    }
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define INF 1<<30
struct edge{int to,cost,time;};
vector<edge> G[101];
int d[101];
bool visited[101];
void dic(int p,int m){
  for(int i=0;i<101;++i) d[i]=INF,visited[i]=false;
  d[p]=0;
  int id;
  for(int i=0;i<m;++i){
    id=-1;
    for(int j=0;j<m;++j){
      if(!visited[j])
        if(id==-1||d[id]>d[j])
          id=j;
    }
    visited[id]=true;
    for(int i=0;i<G[id].size();++i){
      edge e = G[id][i];
      d[e.to]=min(d[e.to],d[id]+e.cost);
    }
  }
}
void dit(int p,int m){
  for(int i=0;i<101;++i) d[i]=INF,visited[i]=false;
  d[p]=0;
  int id;
  for(int i=0;i<m;++i){
    id=-1;
    for(int j=0;j<m;++j){
      if(!visited[j])
        if(id==-1||d[id]>d[j])
          id=j;
    }
    visited[id]=true;
    for(int i=0;i<G[id].size();++i){
      edge e = G[id][i];
      d[e.to]=min(d[e.to],d[id]+e.time);
    }
  }
}
int main(){
  int n,m;
  while(cin>>n>>m,n){
    for(int i=0;i<n;++i){
      int a,b,c,t; cin>>a>>b>>c>>t;
      G[a].push_back((edge){b,c,t});
      G[b].push_back((edge){a,c,t});
    }
    int k; cin>>k;
    for(int i=0;i<k;++i){
      int p,q,r; cin>>p>>q>>r;
      if(r) dit(p,m);
      else dic(p,m);
      cout<<d[q]<<endl;
    }
  }
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#define MAX_M 100
#define INF (1<<21)
using namespace std;

int dp_cost[MAX_M][MAX_M];
int dp_time[MAX_M][MAX_M];
int m;

void warshall_froyd(){
  for(int k=0;k<m;k++){
    for(int i=0;i<m;i++){
      for(int j=0;j<m;j++){
        dp_cost[i][j] = min(dp_cost[i][j], dp_cost[i][k] + dp_cost[k][j]);
        dp_time[i][j] = min(dp_time[i][j], dp_time[i][k] + dp_time[k][j]);
      }
    }
  }
}

int main(){
  int n;
  cin >> n >> m;
  for(int i=0;i<m;i++){
    for(int j=0;j<m;j++){
      dp_time[i][j] = (i==j ? 0 : INF);
      dp_cost[i][j] = (i==j ? 0 : INF);
    }
  }

  for(int i=0;i<n;i++){
    int a,b,cost,time;
    cin >> a >> b >> cost >> time;
    a--;
    b--;
    dp_cost[a][b] = cost; dp_cost[b][a] = cost;
    dp_time[a][b] = time; dp_time[b][a] = time;
  }
  
  warshall_froyd();

  int k,p,q,r;
  cin >> k;
  for(int i=0;i<k;i++){
    cin >> p >> q >> r;
    p--; q--;
    cout << (r == 0 ? dp_cost[p][q] : dp_time[p][q]) << endl;
  }
  cin >> p >> q;
  return 0;
}