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>

typedef long long ll;

using namespace std;

int n;
int G[10010][10010];
int minlen[10010];
bool vis[10010];


void dijkstra(int p){
	memset(minlen,-1,sizeof(minlen));
	memset(vis,0,sizeof(0));
	
	minlen[p] = 0;
	
	while (1){
		int minp = -1;
		int minn = 1<<30;
	
		for(int i = 0 ; i<n ; i++){
			if(!vis[i] && minlen[i]!=-1 && minn>minlen[i]){
				minp = i;
				minn = minlen[i];
			}
		}
		if(minp == -1) break;
		
		vis[minp] = 1;
		for(int j = 0 ; j<n ; j++){
			if(!vis[j] && G[minp][j]!=1<<30){
				if(minlen[j] == -1){
					minlen[j] = minlen[minp]+G[minp][j];
				}
				else if( minlen[j] > minlen[minp]+G[minp][j]){
					minlen[j] = minlen[minp]+G[minp][j];
				}
			}
		}
	}
}

int main(){
	ios::sync_with_stdio(false);
	cin>>n;
	for(int i = 0 ; i<n ; i++)
		for(int j = 0 ; j<n ; j++)
			G[i][j] = 1<<30;
	
	for(int t = 0 ; t<n ; t++){
		int u,k;
		cin>>u>>k;
		for(int i = 0 ; i<k ; i++){
			int to,weight;
			cin>>to>>weight;
			G[u][to] = weight;
		}
	}

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

C++: #include <iostream>
using namespace std;
static const int MAX=101;
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;
    color[0]=GRAY;
    
    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 i=0;i<n;i++){
            if(color[i]!=BLACK && M[u][i]!=INFTY){
                if(d[i]>M[u][i]+d[u]){
                    d[i]=M[u][i]+d[u];
                    color[i]=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;
        }
    }
    
    for(int i=0;i<n;i++){
        int x,y;cin >> x >> y;
        for(int j=0;j<y;j++){
            int z;cin >> z;
            cin >> M[x][z];
        }
    }
    
    dijkstra();
    
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <limits>
#include <queue>
#include <map>
#include <ctime>

using namespace std;

#define rip(i,n,s) for (int i=(s);i<(int)(n);i++)
#define all(a) (a).begin(),(a).end()
typedef pair<long long,int> P;
int main(){
    int n;
    cin >> n;
    vector<vector<P> > da(n,vector<P>(0));
    rip(i,n,0){
        int u,k;
        cin >> u >> k;
        rip(j,k,0){
            long long c;
            int v;
            cin >> v >> c;
            da[u].push_back(make_pair(c,v));
        }
    }
    priority_queue<P,vector<P>,greater<P> > q;
    vector<long long> ans(n,0);
    rip(i,da[0].size(),0){
        q.push(da[0][i]);
    }
    while (!q.empty()){
        P x=q.top();
        q.pop();
        if(ans[x.second]==0 && x.second!=0){
            ans[x.second]=x.first;
            rip(i,da[x.second].size(),0){
                q.push(make_pair(x.first+da[x.second][i].first,da[x.second][i].second));
            }
        }
    }
    rip(i,n,0){
        cout << i << ' ' << ans[i] << endl;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;

#define MAX 100
#define INF INT_MAX
#define WHITE 0
#define GRAY 1
#define BLACK 2

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

void init(int n) {
	for (int i = 0; i < n; i++) {
		col[i] = WHITE;
		for (int j = 0; j < n; j++)
			M[i][j] = INF;
		d[i] = INF;
	}
}

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

void dijkstra(int s) {
	d[s] = 0;
	p[s] = -1;
	while (true) {
		int minc = INF;
		int u;
		for (int i = 0; i < n; i++) {
			if (col[i] != BLACK && d[i] < minc) {
				minc = d[i];
				u = i;
			}
		}
		if (minc == INF) break;
		col[u] = BLACK;
		for (int v = 0; v < n; v++) {
			if (col[v] != BLACK && M[u][v] != INF) {
				if (d[u] + M[u][v] < d[v]) {
					d[v] = d[u] + M[u][v];
					p[v] = u;
					col[v] = GRAY;
				}
			}
		}
	}
}

void output() {
	for (int u = 0; u < n; u++)
		cout << u << " " << d[u] << endl;
}

int main() {
	cin >> n;
	init(n);
	input();
	dijkstra(0);
	output();
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
#define INF 1000000000

int n;
int g[100][100];
int d[100],p[100];

void dijkstra(int start){
  d[start]=0;
  int mn,t,cnt=0;
  while(cnt<=n){
    mn=INF;
    for(int i=0;i<n;i++){
      if(p[i]==0 && mn>d[i]){
	mn=d[i];
	t=i;
      }
    }
    for(int i=0;i<n;i++){
      d[i]=min(g[t][i]+d[t],d[i]);
    }
    p[t]=1;
    cnt++;
  }
}


    
int main(){
  int u,k,v,c;
  for(int i=0;i<100;i++){
    p[i]=0;
    d[i]=INF;
    for(int j=0;j<100;j++){
      if(i==j) g[i][j]=0;
      else g[i][j]=INF;
    }
  }
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>u>>k;
    for(int j=0;j<k;j++){
      cin>>v>>c;
      g[u][v]=c;
    }
  }
  dijkstra(0);
  for(int i=0;i<n;i++){
    cout<<i<<" "<<d[i]<<endl;
  }
  return 0;
}