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 <cstdio>
#include <algorithm>
using namespace std;
int cost[100][100],Time[100][100];
int n,m;
int main() {
	while(scanf("%d %d",&n,&m),n) {
		for(int i=0;i<m;i++) {
			for(int j=0;j<m;j++)  {
				if(i!=j)cost[i][j]=Time[i][j]=1<<27;
				else cost[i][j]=Time[i][j]=0;
			}
		}
		int a,b;
		for(int i=0;i<n;i++) {
			scanf("%d %d",&a,&b);
			scanf("%d %d",&cost[a-1][b-1],&Time[a-1][b-1]);
			cost[b-1][a-1]=cost[a-1][b-1];
			Time[b-1][a-1]=Time[a-1][b-1];
		}
		for(int k=0;k<m;k++) {
			for(int i=0;i<m;i++) {
				for(int j=0;j<m;j++) {
					cost[i][j]=min(cost[i][j],cost[i][k]+cost[k][j]);
					Time[i][j]=min(Time[i][j],Time[i][k]+Time[k][j]);
				}
			}
		}
		int k,p,q,r;
		scanf("%d",&k);
		for(int i=0;i<k;i++) {
			scanf("%d %d %d",&p,&q,&r);
			if(r)printf("%d\n",Time[p-1][q-1]);
			else printf("%d\n",cost[p-1][q-1]);
		}
	}
}

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

#define rep(i,n) for(int i = 0 ; i < n ; i++)

int main(){
	int mon[100][100];
	int tim[100][100];
	int n,m;
	while(cin >> m >> n && n ){
		rep(i,n)rep(j,n) mon[i][j] = tim[i][j] = 1e9;
		for(int i = 0 ; i < m ; i++){
			int a,b,c,d;
			cin >> a >> b >> c >> d;
			a--,b--;
			mon[a][b] = mon[b][a] = c;
			tim[a][b] = tim[b][a] = d;
		}
		rep(i,n)rep(j,n)rep(k,n){
			mon[j][k] = min(mon[j][k],mon[j][i]+mon[i][k]);
			tim[j][k] = min(tim[j][k],tim[j][i]+tim[i][k]);
		}
		int R;
		cin >> R;
		rep(i,R){
			int a,b,c;
			cin >> a >> b >> c;
			a--,b--;
			if(c) cout << tim[a][b];
			else cout << mon[a][b];
			cout << endl;
		}
	}
}

C++: #include<map>
#include<set>
#include<list>
#include<cmath>
#include<queue>
#include<stack>
#include<cstdio>
#include<string>
#include<vector>
#include<complex>
#include<cstdlib>
#include<cstring>
#include<climits>
#include<numeric>
#include<sstream>
#include<iostream>
#include<algorithm>
#include<functional>
#include<cctype>

#define mp make_pair
#define pb push_back
#define REP(i,a,n) for(int i = a;i < (n);i++)
#define rep(i,n) for(int i = 0;i < (n);i++)
#define all(s) s.begin(), s.end()
#define rall(s) s.rbegin(), s.rend()
#define range(x,min,max) ((min) <= (x) && (x) <= (max)) 

using namespace std;

typedef long long LL;
typedef vector<int> VI;
typedef vector<vector<int> > VII;
typedef pair<int,int> PII;

const int DX[]={1,0,-1,0},DY[]={0,-1,0,1};

int n,m;
VI A,B;
VII C(2);

int dijkstra(int s,int g,int mode){
	VI dist(m + 1,INT_MAX);
	priority_queue<PII,vector<PII >,greater<PII > > que;
	que.push(mp(0,s));
	dist[s] = 0;
	while(!que.empty()){
		int d = que.top().first, u = que.top().second;
		que.pop();
		if(dist[u] < d) continue;
		rep(i,n){
			if(u == A[i] && dist[u] + C[mode][i] < dist[B[i]]){
				dist[B[i]] = dist[u] + C[mode][i];
				que.push(mp(dist[B[i]],B[i]));
			}
			if(u == B[i] && dist[u] + C[mode][i] < dist[A[i]]){
				dist[A[i]] = dist[u] + C[mode][i];
				que.push(mp(dist[A[i]],A[i]));
			}
		}
	}
	return dist[g];
}

int main(){
	cin.tie(0);
   	ios::sync_with_stdio(false);
	while(1){
		cin >> n >> m;
		if(n == 0 && m == 0) break;
		
		rep(i,n){
			int a,b,c,t;
			cin >> a >> b >> c >> t;
			A.pb(a);
			B.pb(b);
			C[0].pb(c);
			C[1].pb(t);
		}
		int k;
		cin >> k;
		rep(i,k){
			int s,g,mode;
			cin >> s >> g >> mode;
			int ans = dijkstra(s,g,mode);
			cout << ans << endl;
		}
	}
	return 0;
}

C++: #include <iostream>
#include <queue>
#include <utility>
#include <vector>
#include <functional>

struct Node {
	std::vector<int> edgesDest;
	std::vector<int> edgesCost[2];

	bool done = false;
	int cost = -1;

	bool operator < (const Node& n) {
		return cost < n.cost;
	}
};

int main() {
	int n, m;
	std::vector<Node> nodes;
	using Pair = std::pair<int, int>;

	while (std::cin >> n >> m) {
		if (n == 0 && m == 0)
			break;

		nodes.clear();
		nodes.resize(m);
		for (int i = 0; i < n; ++i) {
			int a, b, c, t;
			std::cin >> a >> b >> c >> t;

			nodes[a - 1].edgesDest.push_back(b - 1);
			nodes[a - 1].edgesCost[0].push_back(c);
			nodes[a - 1].edgesCost[1].push_back(t);

			nodes[b - 1].edgesDest.push_back(a - 1);
			nodes[b - 1].edgesCost[0].push_back(c);
			nodes[b - 1].edgesCost[1].push_back(t);
		}

		int k;
		std::cin >> k;
		for (int i = 0; i < k; ++i) {
			for (int j = 0; j < nodes.size(); ++j)
				nodes[j].done = false, nodes[j].cost = -1;

			int p, q, r;
			std::cin >> p >> q >> r;
			--p, --q;

			nodes[p].cost = 0;

			std::priority_queue<Pair, std::vector<Pair>, std::greater<Pair>> queue;
			queue.push(Pair(0, p));
			while (!queue.empty()) {
				const Pair& qtop = queue.top();
				Node& node = nodes[qtop.second];

				if (node.done) {
					queue.pop();
					continue;
				}
				if (qtop.second == q) {
					std::cout << node.cost << std::endl;
					break;
				}
				queue.pop();

				node.done = true;
				for (int j = 0; j < node.edgesDest.size(); ++j) {
					int dest = node.edgesDest[j];
					int cost = node.cost + node.edgesCost[r][j];

					if (nodes[dest].cost < 0 || cost < nodes[dest].cost) {
						nodes[dest].cost = cost;
						queue.push(Pair(cost, dest));
					}
				}
			}
		}
	}

	return 0;
}