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]
					t_newlen := t_dist[i][k] + t_dist[k][j]
					if c_newlen < c_dist[i][j] {
						c_dist[i][j] = c_newlen
						c_prev[i][j] = c_prev[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>
#include <vector>
#include <array>
#include <algorithm>
#include <iterator>
using namespace std;

struct AboutTo;

class Node{
public:
	int aa;
	int Lowest;
	bool IsSelected;
	vector<AboutTo> ToCollection;
	Node(){
		Lowest = 2147483647/2;
		IsSelected = false;
	}
	void Reset(){
		Lowest = 2147483647/2;
		IsSelected = false;
	}
};
struct AboutTo{
	Node* To;
	int Cost;
	int Time;
};

int GetShortest(int a,Node GoalNode, int b, vector<Node> &aNodeCol, const int IsTime){
	aNodeCol[a].IsSelected = true;
	int TempMin = 2147483647/2;
	int aNode;
	Node fad;
	for (unsigned int i = 0; i < aNodeCol.size(); ++i){
		if (aNodeCol[i].IsSelected){
			for (unsigned int j = 0; j < aNodeCol[i].ToCollection.size(); ++j){
				if (!(*(aNodeCol[i].ToCollection[j].To)).IsSelected){
					if (IsTime){
						if (TempMin>aNodeCol[i].Lowest + aNodeCol[i].ToCollection[j].Time){
							TempMin = aNodeCol[i].Lowest + aNodeCol[i].ToCollection[j].Time;
							aNode = (*(aNodeCol[i].ToCollection[j].To)).aa;
							fad = *aNodeCol[i].ToCollection[j].To;
						}
					}
					else{
						if (TempMin>aNodeCol[i].Lowest + aNodeCol[i].ToCollection[j].Cost){
							TempMin = aNodeCol[i].Lowest + aNodeCol[i].ToCollection[j].Cost;
							aNode = (*(aNodeCol[i].ToCollection[j].To)).aa;
							fad = *aNodeCol[i].ToCollection[j].To;
						}
					}
				}
			}
		}
	}
	if (b != aNode){
		aNodeCol[aNode].Lowest = TempMin;
		return GetShortest(aNode,GoalNode, b, aNodeCol, IsTime);
	}
	/*if (GoalNode != aNode){
		aNodeCol[aNode].Lowest = TempMin;
		return GetShortest(aNode, GoalNode, b, aNodeCol, IsTime);
	}*/
	return TempMin;
}

int main(){
	int n, m;
	cin >> n >> m;
	vector<Node> NodeCollection;
	for (int i = 0; i < m; ++i){
		Node aNode;
		aNode.aa = i;
		NodeCollection.push_back(aNode);
	}

	for (int i = 0; i < n; ++i){
		int a, b, cost, time;
		cin >> a >> b >> cost >> time;
		NodeCollection[a - 1].ToCollection.push_back({ &NodeCollection[b - 1], cost, time });
		NodeCollection[b - 1].ToCollection.push_back({ &NodeCollection[a - 1], cost, time });
	}
	int k;
	cin >> k;
	for (int i = 0; i < k; ++i){
		int p, q, r;
		cin >> p >> q >> r;
		NodeCollection[p - 1].Lowest = 0;
		cout << GetShortest(p - 1, q - 1, NodeCollection, r) << endl;
		for (auto i = NodeCollection.begin(); i != NodeCollection.end(); ++i){
			(*i).Reset();
		}
	}
	cin >> k >> k;
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef pair<int,int> P;
struct Graph{
  Graph(int n):E(n),d(n){}
  vector<vector<tuple<int,int,int>>>E;
  vector<int>d;
  void add_edge(int a,int b,int c,int d){
    E[a].push_back(make_tuple(b,c,d));
  }
  void dijkstra(int s,int f){
    priority_queue<P,vector<P>,greater<P>>q;
    fill(d.begin(),d.end(),1e9);
    q.push({d[s]=0,s});
    while(q.size()){
      auto p=q.top();q.pop();
      if(p.first>d[p.second])continue;
      for(auto& a:E[p.second]){
        int x=get<0>(a),y=get<1>(a)+p.first;
        if(f)y=get<2>(a)+p.first;
        if(y<d[x])d[x]=y,q.push({y,x});
      }
    }
  }
};
main(){
  int n,m,a,b,c,d,k;
  while(cin>>n>>m,n){
    Graph E(m);
    for(int i=0;i++<n;E.add_edge(--a,--b,c,d),E.add_edge(b,a,c,d))cin>>a>>b>>c>>d;
    cin>>k;
    for(int i=0;i++<k;cout<<E.d[--b]<<endl){
      cin>>a>>b>>c;
      E.dijkstra(--a,c);
    }
  }
}

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

const int N = 110;
int timu[N][N];
int cost[N][N];

int main()
{
  int n,m;
  while(cin >> n >> m ,n|m)
  {
    for(int i=0;i<N;++i)
    for(int j=0;j<N;++j)
      timu[i][j] = cost[i][j] = 1<<30;

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

    for(int k=0;k<N;++k)
    for(int i=0;i<N;++i)
    for(int j=0;j<N;++j)
    {
      cost[i][j] = min(cost[i][j], cost[i][k] + cost[k][j]);
      timu[i][j] = min(timu[i][j], timu[i][k] + timu[k][j]);
    }

    int k;
    cin >> k;
    while(k--)
    {
      int p,q,r;
      cin >> p >> q >> r;
      if(r)
        cout << timu[p][q] << endl;
      else
        cout << cost[p][q] << endl;
    }
  }
  return 0;
}

C++: #include <cstdio>
#include <cstring>
#include <algorithm>
#define INF (1145141919)
using namespace std;

int n;

int from[6000];
int to[6000];
int cost[6000][2];

int d[100];
int r;
void Search(int s)
{
	for (int i = 0; i < 100; i++){
		d[i] = INF;
	}
	d[s] = 0;
	
	while (true){
		bool update = false;
		
		for (int i = 0; i < n * 2; i++){
			if (d[from[i]] != INF && d[to[i]] > d[from[i]] + cost[i][r]){
				d[to[i]] = d[from[i]] + cost[i][r];
				update = true;
			}
		}
		
		if (!update){
			break;
		}
	}
}
	

int main()
{	
	int m;
	while (scanf("%d %d", &n, &m), n + m){
		for (int i = 0; i < n; i++){
			int a, b, c, t;
			scanf("%d %d %d %d", &a, &b, &c, &t);
			a--;
			b--;
			
			
			from[i * 2] = a;
			to[i * 2] = b;
			cost[i * 2][0] = c;
			cost[i * 2][1] = t;
			
			from[i * 2 + 1] = b;
			to[i * 2 + 1] = a;
			cost[i * 2 + 1][0] = c;
			cost[i * 2 + 1][1] = t;
		}
		
		int k;
		scanf("%d", &k);
		
		for (int i = 0; i < k; i++){
			int p, q;
			scanf("%d %d %d", &p, &q, &r);
			p--;
			q--;
			
			Search(p);
			printf("%d\n", d[q]);
		}
	}
	
	return 0;
}