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

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define repr(i, n) for (int i = (n); i >= 0; --i)
#define FOR(i, m, n) for (int i = (m); i < (n); ++i)
#define FORR(i, m, n) for (int i = (m); i >= (n); --i)
using namespace std;
typedef long long ll;
const ll mod = 1000000007;
const ll mod2 = 998244353;
const int INF = 1000000005;
const int MAX = 105;

class edge {
  public:
  int t, c;

  edge(int t = -1, int c = INF): t(t), c(c) {}

  bool operator < (const edge &e) const {
    return c > e.c;
  }
};

vector<edge> to[MAX];
bool seen[MAX];
int d[MAX], n;

void dijkstra(int u) {
  d[u] = 0;
  while (1) {
    seen[u] = true;
    for (edge e: to[u]) {
      if (seen[e.t]) continue;
      d[e.t] = min(d[e.t], d[u] + e.c);
    }

    int mind = INF;
    rep(i, n) {
      if (seen[i]) continue;
      if (d[i] < mind) {
        u = i;
        mind = d[i];
      }
    }

    if (mind == INF) break;
  }
}

int main() {
  cin >> n;
  int u, k;
  edge e;
  rep(i, n) {
    cin >> u >> k;
    rep(j, k) {
      cin >> e.t >> e.c;
      to[u].push_back(e);
    }
  }

  rep(i, n) {
    seen[i] = false;
    d[i] = INF;
  }

  dijkstra(0);

  rep(i, n) cout << i << " " << d[i] << endl;
  
  return 0;
}

C++: #include <iostream>
#include <cstdio>
using namespace std;
int a[100][100], n;
int d[200];
void duyet(int u)
{
    for(int v=0; v<n; v++)
    {
        if(a[u][v]>0 && d[v]>(d[u]+a[u][v]))
        {
            d[v]=d[u]+a[u][v];
            duyet(v);
        }
    }
}
int main()
{
    long long int s,t,u;
    cin>>n;
    for(int i=0; i<n; i++)
    {
        cin>>s>>t;
        for(int j=1; j<=t; j++)
        {
            cin>>s>>u; a[i][s]=u;
        }
        d[i]=1e6;
    }
    d[0]=0;
    duyet(0);
    for(int i=0; i<n; i++)
    {
        cout<<i<<" "<<d[i]<<endl;
    }
    return 0;
}

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

struct Edge{ int to,cost; };

typedef pair<int,int> P;
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

void dijkstra(Graph &G,vector<int> &d,int n,int s){
	priority_queue< P, vector<P>, greater<P> > que;
	fill(d.begin(),d.end(),INT_MAX);
	d[s]=0;
	que.push(P(0,s));
	
	while(!que.empty()){
		P p=que.top();
		que.pop();
		
		int a=p.second;
		if (d[a]<p.first){
			continue;
		}
		for (int i=0;i<G[a].size();i++){
			Edge e = G[a][i];
			if (d[e.to]>d[a]+e.cost){
				d[e.to]=d[a]+e.cost;
				P p2=P(d[e.to],e.to);
				que.push(p2);
			}
		}
	}
}

int main(){
	int n,i,j,k;
	vector<int> d(n);
	Edge e;
	
	cin >> n;
	
	Graph G(n);
	
	for (i=0;i<n;i++){
		cin >> k >> k;
		for (j=0;j<k;j++){
			cin >> e.to >> e.cost;
			G[i].push_back(e);
		}
	}
	
	dijkstra(G,d,n,0);
	
	for (i=0;i<n;i++){
		cout << i << " " << d[i] << endl;
	}
	
	return 0;
}

C++: #include<iostream>
int main(){
  int u,k,C,V,A[1000][1000],D[1000][1000],n;
  std::cin >> n;
  for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = 200001;
  for(int i=0;i<n;i++){ 
    std::cin >> u >> k;
    for(int j=0;j<k;j++){
      std::cin >> V >> C;
      D[u][V] = C;
    } 
  }
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j]= std::min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++)std::cout << i << " " << D[0][i] << std::endl;
  return 0;
}