Go: // ダイクストラのアルゴリズム
package main

import (
	"bufio"
	"fmt"
	"log"
	"math"
	"os"
	"strconv"
	"strings"
)

type color int

const (
	white color = iota // 未訪問
	mst                // MSTとして確定
)

// 頂点
type node struct {
	num       int         // 頂点の番号
	weights   map[int]int // 重みMAP
	parent    *node       // MSTへの重み最小の親
	distFromS int         // 始点からの距離
	color     color
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	n := eGetInt(scanner)

	nodes := make([]*node, n)
	for i := 0; i < n; i++ {
		weights := eAtoi((strings.Fields(eGetline(scanner))))
		v := &node{weights[0], make(map[int]int, weights[1]), nil, math.MaxInt32, white}
		for j := 0; j < weights[1]; j++ {
			k := weights[j*2+2] // 相手の頂点名
			w := weights[j*2+3] // 重み
			v.weights[k] = w
		}
		nodes[i] = v
	}

	// 初回はnode[0]がMSTに入るように
	nodes[0].distFromS = 0

	for { // 全部チェックするまで

		// どの頂点を新たにMSTに取り込むか

		var minNode *node
		min := math.MaxInt32
		for _, v := range nodes {
			if v.color == mst {
				continue
			}
			if v.distFromS < min {
				min = v.distFromS
				minNode = v
			}
		}
		if minNode == nil {
			// すべて完了している.
			break
		}

		// MSTに追加する頂点決定
		minNode.color = mst

		// fmt.Printf(">[%v]\n", minNode)
		// MSTに属していない頂点それぞれについて,Startからの最小の重みの距離を更新
		for i, v := range nodes {
			if v.color == mst {
				continue
			}
			w, ok := minNode.weights[i]
			if !ok {
				// minNodeと接してない
				continue
			}

			if minNode.distFromS+w < v.distFromS {
				// minNode経由の距離がもっとも重みが少ないので親を変更
				v.distFromS = minNode.distFromS + w
				v.parent = minNode
				// fmt.Printf("[%v %v]\n", v, minNode)
			}
		}
		// fmt.Printf("<\n")
	}

	for i, v := range nodes {
		fmt.Printf("%d %d\n", i, v.distFromS)
	}
}

func eGetInt(scanner *bufio.Scanner) int {
	t := eAtoi(strings.Fields(eGetline(scanner)))
	return t[0]
}

func eGetline(p *bufio.Scanner) string {
	if !p.Scan() {
		if err := p.Err(); err != nil {
			log.Fatal(err.Error())
		}
		return ""
	}
	return p.Text()
}

func eAtoi(s []string) []int {
	ints := make([]int, len(s))
	var err error
	for i, e := range s {
		ints[i], err = strconv.Atoi(e)
		if err != nil {
			log.Fatal(err.Error())
		}
	}
	return ints
}

C++: #include<bits/stdc++.h>

std::vector<int> color;
std::vector<std::vector<int>> M;
std::vector<int> d;
std::vector<int> p;
int INF = 1001001001;
int sum = 0;

void dijkstra(int n){
    for(int i = 0; i < n; i++){
        color[i] = 0;
        d[i] = INF;
    }

    d[0] = 0;
    p[0] = -1;

    while(true){
        int u;
        int mincost = INF;
        for(int i = 0; i < n; i++){
            if(color[i] != 1 && d[i] < mincost){
                mincost = d[i];
                u = i;
            }
        }

        if(mincost == INF){
            break;
        }

        color[u] = 1;

        for(int i = 0; i < n; i++){
            if(color[i] != 1 && M[u][i] != -1){
                if(d[u] + M[u][i] < d[i]){
                    d[i] = d[u] + M[u][i];
                }
            }
        }

    }
    
    for(int i = 0; i < d.size(); i++){
        sum += d[i];
    }

}

int main(void){
    int n;
    std::cin >> n;

    color.resize(n);

    M.resize(n, std::vector<int>(n));
    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            M[i][j] = INF;
        }
    }

    d.resize(n);
    p.resize(n);

    int u, k, v;

    for(int i = 0; i < n; i++){
        std::cin >> u >> k;
        for(int i = 0; i < k; i++){
            std::cin >> v;
            std::cin >> M[u][v];
        }
    }
    
    
    dijkstra(n);
    
    for(int i = 0; i < n; i++){
        std::cout << i << " " << d[i] << std::endl;
    }

    return 0;
}

C++: #include <iostream>

using namespace std;

#define MAX 100
#define WHITE 0
#define GRAY 1
#define BLACK 2
#define INFTY 99999999

int color[MAX];
int M[MAX][MAX];
int d[MAX];
int p[MAX];
int n;

int dijkstra(int s)
{

	int mincost;
	int u;

	for (int i = 0; i < n; i++) {
		d[i] = INFTY;
		p[i] = -1;
	}
	d[s] = 0;

	while (true) {
		mincost = INFTY;

		for (int i = 0; i < n; i++) {
			if (color[i] != BLACK&&d[i] < mincost) {
				mincost = d[i];
				u = i;
			}
		}

		if (mincost == INFTY) {
			break;
		}

		color[u] = BLACK;

		for (int i = 0; i < n; i++) {
			if (color[i] != BLACK&&M[u][i] != -1) {
				if (d[u] + M[u][i] < d[i]) {
					d[i] = d[u] + M[u][i];
					p[i] = u;
					color[i] = GRAY;
				}
			}
		}


	}


	int sum = 0;

	for (int i = 0; i < n; i++) {
		sum += d[i];
	}

	return sum;


}

int main(void)
{

	cin >> n;

	int u;
	int k;
	int v;

	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v;
			cin >> M[u][v];
		}
	}

	for (int i = 0; i < n; i++) {
		cout << i << " " << dijkstra(i) << endl;
	}

	return 0;
}

C++: #include <iostream>
using namespace std;
static const int MAX = 100;
static const int INFTY = (1<<21);

enum Color {
  WHITE, GRAY, BLACK
};

int M[MAX][MAX];
int d[MAX];
int p[MAX];
Color color[MAX];
int n;

void init() {
  for (int i = 0; i < n; i++) {
    color[i] = WHITE;
    d[i] = INFTY;
  }
}

void dijkstra(int s) {
  init();
  d[s] = 0;
  p[s] = -1;

  while (true) {
    int mincost = INFTY;
    int u;
    for (int i = 0; i < n; i++) {
      if (color[i] != BLACK && d[i] < mincost) {
        mincost = d[i];
        u = i;
      }
    }
    if (mincost == INFTY) break;

    color[u] = BLACK;
    for (int v = 0; v < n; v++) {
      if (M[u][v] != INFTY && color[v] != BLACK) {
        if (d[u] + M[u][v] < d[v]) {
          d[v] = d[u] + M[u][v];
          p[v] = u;
          color[v] = GRAY;
        }
      }
    }
  }
}

int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < n; j++) {
      M[i][j] = INFTY;
    }
  }
  for (int i = 0; i < n; i++) {
    int elem, index, v;
    cin >> v >> elem;
    for (int j = 0; j < elem; j++) {
      int u;
      cin >> u;
      cin >> M[v][u];
    }
  }
  dijkstra(0);
  for (int i = 0; i < n; i++) {
    cout << i << " " << d[i] << endl;
  }
  return 0;
}

C++: // http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_12_B&lang=jp
//
#include <stdio.h>
#include <iostream>
#include <vector>
using namespace std;

#define NUM 100
#define BLACK 0
#define WHITE 1
#define INF 100000000
#define NIL -1

vector<pair<int,int>> A[NUM];
int V[NUM];
int color[NUM];

void init(){
    for(int i = 0; i < NUM; i++){
        V[i] = INF;
        color[i] = WHITE;
    }
}

int main(void){
    init();

    int n;
    scanf("%d", &n);
    for(int i = 0; i < n; i++){
        int u, k;
        scanf("%d", &u);
        scanf("%d", &k);

        for(int j = 0; j < k; j++){
            int v, c;
            scanf("%d", &v);
            scanf("%d", &c);
            A[u].push_back(make_pair(v, c));
        }
    }

    int next_node = 0;
    V[0] = 0;
    while(1){
        color[next_node] = BLACK;
        for(int i = 0; i < A[next_node].size(); i++){
            int v = A[next_node][i].first;
            int c = A[next_node][i].second;
            V[v] = min(V[v], V[next_node] + c);
        }

        next_node = NIL;
        int min_dist = INF;
        for(int i = 0; i < n; i++){
            if(color[i] == BLACK){
                continue;
            }
            if(V[i] < min_dist){
                min_dist = V[i];
                next_node = i;
            }
        }

        if(next_node == NIL){
            break;
        }
    }
    for(int i = 0; i < n; i++){
        printf("%d %d\n", i, V[i]);
    }
}