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 <cstdio>
#include <vector>
#include <queue>
using namespace std;
const int MAXN = 1e4 + 7, INF = 5e5 + 7;
int d[MAXN];
struct node {
	int id, dist;
	node(int id, int dist) :id(id), dist(dist) {}
	bool operator < (const node &rhs) const {
		return dist > rhs.dist;
	}
};
vector<pair<int, int> > G[MAXN];
priority_queue<node> nodes;
int main() {
    int n;
    scanf("%d", &n);
    for (int i = 1; i < n; i++) {
    	d[i] = INF;
	}
    for (int i = 0; i < n; i++) {
    	int u, k;
    	scanf("%d%d", &u, &k);
    	for (int j = 0; j < k; j++) {
    		int v, c;
    		scanf("%d%d", &v, &c);
    		G[u].push_back(make_pair(v, c));
		}
	}
	nodes.push(node(0, 0));
	while (!nodes.empty()) {
		node tmp = nodes.top();
		nodes.pop();
		if (tmp.dist > d[tmp.id]) continue;
		int cnt = G[tmp.id].size();
		for (int i = 0; i < cnt; i++) {
			if (d[G[tmp.id][i].first] > d[tmp.id] + G[tmp.id][i].second) {
				d[G[tmp.id][i].first] = d[tmp.id] + G[tmp.id][i].second;
				nodes.push(node(G[tmp.id][i].first, d[G[tmp.id][i].first]));
			}
		}
	}
	for (int i = 0; i < n; i++) {
		printf("%d %d\n", i, d[i]);
	}
	return 0;
}

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

int n,M[100][100];

void dikstra(){
  int u,minu,d[100],p[100],color[100];
  for (int i = 0; i < n; i++) {
    color[i] = 0;
    d[i] = INFTY;
  }
  d[0] = 0;
  color[0] = 1;

  while (1) {
    minu = INFTY;
    u = -1;
    for (int i = 0; i < n; i++) {
      if (color[i] != 2 && d[i] < minu) {
        minu = d[i];
        u = i;
      }
    }
    if (u == -1)break;
    color[u] = 2;

    for (int v = 0; v < n; v++) {
      if (color[v] != 2 && M[u][v] != INFTY) {
        if (d[u] + M[u][v] < d[v]) {
          d[v] = d[u] + M[u][v];
          color[v] = 1;
        }
      }
    }
  }
  for (int i = 0; i < n; i++) {
    cout << i << " " <<(d[i] == INFTY ? -1 : d[i])<< endl;
  }

}
int main() {
  int u,v,k,c;
  cin >> n/* variable */;
  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++) {
    cin >> u >> k;
    for (int j = 0; j < k; j++) {
      cin >> v >> c;
      M[u][v] = c;
    }
  }

  dikstra();

  return 0;
}

C++: #include<stdio.h>
#include<algorithm>
#include<iostream>
using namespace std;
#define INF 1<<21
int main()
{
	long long int min,n,u,k,v,c,dist[100][100],s,cost[100],t[100],l=1;
	cin>>n;
	for(int i=0;i<n;i++)
	{
		for(int j=0;j<n;j++)
		{
			dist[i][j]=INF;
			cost[i]=INF;
			t[i]=-1;
		}
	}
	min=INF;
	dist[0][0]=0;
	for(int i=1;i<=n;i++)
	{
		cin>>u;
		cin>>k;
		for(int i=1;i<=k;i++)
		{
			cin>>v>>c;
			dist[u][v]=c;
		}
	}
	s=0;
	cost[s]=0;
	while(l!=n)
	{
		for(int i=0;i<n;i++)
		{
			if(dist[s][i]!=INF)
			{
				if(cost[s]+dist[s][i]<cost[i])
				{
					cost[i]=cost[s]+dist[s][i];
				}
				
			}
		}
		t[s]=1;
		for(int i=1;i<n;i++)
		{
			if(cost[i]<min&&t[i]==-1)
			{
				min=cost[i];
				s=i;
			}
		}
		min=INF+1;
		l++;
	}
	for(int i=0;i<n;i++)
	{
		cout<<i<<" "<<cost[i]<<endl;
	}
	return 0;
}

C++: #include<iostream>
using namespace std;
static const int MAX = 100;
static const int INFTY = (1<<21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n,M[MAX][MAX];
void dijkstra(){
  int minv;
  int d[MAX],color[MAX];
  for(int i=0;i<n;i++){
    d[i]=INFTY;
    color[i]=WHITE;
  }
  d[0]=0;
  while(1){
    minv=INFTY;
    int u=-1;
    for(int i=0;i<n;i++){
      if(minv > d[i] && color[i] != BLACK){
	u=i;
      minv=d[i];
    }
  }
  if(u==-1) break;
  color[u]=BLACK;
  for(int v=0;v<n;v++){
    if(color[v] != BLACK && M[u][v] != INFTY){
      if(d[v]>d[u]+M[u][v]){
	d[v]=d[u]+M[u][v];
	color[v]=GRAY;
      }
    }
  }
  }
  for(int i=0;i<n;i++){
    cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << endl;
  }
}
int main(){
  cin>>n;
  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
      M[i][j] = INFTY;
    }
  }
  int k,c,u,v;
  for(int i=0;i<n;i++){
  cin >> u >> k;
  for(int j=0;j<k;j++){
  cin >> v >> c;
  M[u][v]=c;
  }
  }
  dijkstra();
  return 0;
}