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;

#define STAT_MAX 100
#define LINE_MAX 3000

int main(){
	int n,m,a,b;
	int start,goal,flg;

	int i,j;

	int lineNum;
	int lineCost[LINE_MAX][2];	//[lineId][flg]?????????????????????????????????

	int statNum;
	int statToNum[STAT_MAX];	//[statId]??\?¶???????????????????????????°
	int statTo[STAT_MAX][STAT_MAX];	//[statId][i]??\?¶??????????????????????????????????????????£????????????
	int statToId[STAT_MAX][STAT_MAX];	//[statId][i]??\?¶?????????????????????????id

	int yetNum;
	int yetId[STAT_MAX];	//?????¢?´¢???statId
	int yetDepth[STAT_MAX];	//?????¢?´¢???stat???????§???????
	int yetCost[STAT_MAX];	//?????¢?´¢???stat?????????????????????????????????
	int nowId,nowDepth,nowCost;

	int searchedNum;
	int searchedId[STAT_MAX];	//??¢?´¢?????????ID?????????
	int searchedTotal[STAT_MAX];	//?????????????´???????
	int result;

	while(1){
		//???????????±
		cin>>n>>m;if(!n && !m) break;
		lineNum=n;statNum=m;
		while(m--) statToNum[m]=0;
		for(i=0;i<n;i++){
			cin>>a>>b>>lineCost[i][0]>>lineCost[i][1];
			a--;b--;
			statTo[a][statToNum[a]]=b;statTo[b][statToNum[b]]=a;
			statToId[a][statToNum[a]]=i;statToId[b][statToNum[b]]=i;
			statToNum[a]++;statToNum[b]++;
		}
		//???????????????
		cin>>n;
		while(n--){
			cin>>start>>goal>>flg;
			start--;goal--;
			result=-1;yetNum=0;searchedNum=0;
			yetId[yetNum]=start;yetDepth[yetNum]=-1;yetCost[yetNum]=0;yetNum++;
			while(yetNum--){
				//?????¢?´¢stat???????????????
				nowId=yetId[yetNum];
				nowDepth=yetDepth[yetNum];
				nowCost=yetCost[yetNum];
				//??¢?´¢???????????????
				searchedId[searchedNum]=nowId;
				searchedTotal[searchedNum]=searchedNum?searchedTotal[searchedNum-1]+nowCost:nowCost;
				searchedNum++;

				if(nowId==goal){
					if(result==-1 || searchedTotal[searchedNum-1]<result) result=searchedTotal[searchedNum-1];
					if(yetNum!=0) searchedNum=yetDepth[yetNum-1];
				}else{
					//??\?¶?????????????????§????????´¢????????¢?´¢??????yet?????????
					m=yetNum;	//??????????????????
					for(i=0;i<statToNum[nowId];i++){
						for(j=0;j<searchedNum-1;j++){
							if(statTo[nowId][i]==searchedId[j]) break;
						}
						if(j!=searchedNum-1) continue;
						yetId[yetNum]=statTo[nowId][i];
						yetDepth[yetNum]=nowDepth+1;
						yetCost[yetNum]=lineCost[statToId[nowId][i]][flg];
						yetNum++;
					}
					//??°?????§??????????????????
					if(m==yetNum){
						if(yetNum!=0) searchedNum=yetDepth[yetNum-1];
					}
				}
			}
			cout<<result<<endl;
		}
	}
	return 0;
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <vector>
#include <set>
#include <map>
#include <sstream>
#include <string>
#include <cstdio>
#include <stack>
#include <queue>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cstring>
#include <tuple>
#include <utility>
#include <list>
#include <cmath>
#include <unordered_map>

using namespace std;

typedef long long LL;
typedef vector<int> Array;
typedef pair<int, int> P;

const int INF = 1 << 29;
const LL MOD = 100000;
#define rep(i,n) for(int i=0;i<(int)n;++i)
#define all(c) (c).begin(), (c).end()

struct edge{ int to, cost; edge(int t, int c) :to(t), cost(c){} };

int main()
{
	//while (cin >> n)
	stringstream ss;
	//ss << "result" << i + 1 << ".txt";
	//FILE* fp_out = freopen(ss.str().c_str(), "w", stdout);

	int n, m;
	while (cin >> n >> m && n)
	{
		vector<vector<int>> times(m, vector<int>(m, INF));
		vector<vector<int>> costs(m, vector<int>(m, INF));
		rep(i, n)
		{
			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;
		}

		rep(k, m) rep(i, m) rep(j, m)
		{
			costs[i][j] = min(costs[i][j], costs[i][k] + costs[k][j]);
			times[i][j] = min(times[i][j], times[i][k] + times[k][j]);
		}

		int k; cin >> k;
		rep(i, k)
		{
			int p, q, r; cin >> p >> q >> r;
			p--; q--;
			cout << (r ? times[p][q] : costs[p][q]) << endl;
		}
	}

	return 0;
}

C++: #include<stdio.h>
#include<algorithm>
#include <map>
#include <list>
#include <stack>
#include <queue>
#include <vector>
#include <iostream>
#include <functional>
#include <time.h>
using namespace std;
clock_t fi, endtime;

const int INF = INT16_MAX;
const int r_c = 0;
const int r_t = 1;
const int MAX_V = 100;
const int MAX_E = 6000;

int n, m, a, b, c, t;
int k, p, q, r;

int wft[MAX_V][MAX_V] = { 0 };
int wfc[MAX_V][MAX_V] = { 0 };

int main()
{
	scanf_s("%d %d", &n, &m);
	for (int i = 0; i < m; ++i) {
		for (int j = 0; j < m; ++j) {
			wfc[i][j] = INF; wft[i][j] = INF;
		}
	}

	for (int i = 0; i < n; ++i) {
		scanf_s("%d %d %d %d", &a, &b, &c, &t);
		wft[a - 1][b - 1] = t;  wft[b - 1][a - 1] = t;
		wfc[a - 1][b - 1] = c;  wfc[b - 1][a - 1] = c;
	}
	for (int k = 0; k < m; ++k) {
		for (int i = 0; i < m; ++i) {
			for (int j = 0; j < m; ++j) {
				if (wft[i][j] > wft[i][k] + wft[k][j]) { wft[i][j] = wft[i][k] + wft[k][j]; }
				if (wfc[i][j] > wfc[i][k] + wfc[k][j]) { wfc[i][j] = wfc[i][k] + wfc[k][j]; }
			}
		}
	}
	scanf_s("%d", &k);
	int ans = 0;
	for (int i = 0; i < k; ++i){
		scanf_s("%d %d %d", &p, &q, &r);
		if (p == 0 && q == 0) break;
		if (r == 0) { ans = wfc[p - 1][q - 1]; }
		else { ans = wft[p - 1][q - 1]; }
		printf("%d\n", ans);
	}

}