Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type DirectedGraphNodeID int

type DirectedGraphNode struct {
	key         DirectedGraphNodeID
	adjacents   []*DirectedGraphNode
	costs       []int
	distance    int
	predecessor *DirectedGraphNode
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for i := 0; i < nNodes; i++ {
		node := DirectedGraphNode{}
		node.key = DirectedGraphNodeID(i)
		node.distance = infty
		graph.nodes[i] = &node
	}
	return &graph
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(i, j DirectedGraphNodeID, cost int) {
	g.nodes[i].adjacents = append(g.nodes[i].adjacents, g.nodes[j])
	g.nodes[i].costs = append(g.nodes[i].costs, cost)
}

func (g *DirectedGraph) print() {
	for i := 0; i < len(g.nodes); i++ {
		node := g.nodes[i]
		key := node.key
		strings := []string{strconv.Itoa(int(key)), strconv.Itoa(node.distance)}
		for j := 0; j < len(node.adjacents); j++ {
			nodeJ := fmt.Sprintf("(%v, %v)", node.adjacents[j].key, node.costs[j])
			strings = append(strings, nodeJ)
		}
		fmt.Printf("%v\n", strings)
	}
}

func (g *DirectedGraph) relaxEdge(l, r *DirectedGraphNode, w int) {
	if r.distance > l.distance+w {
		// fmt.Printf("%v -> %v, %v\n", l.key, r.key, l.distance+w)
		r.distance = l.distance + w
		r.predecessor = l
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	graph := newDirectedGraph(nNodes)

	for i := 0; i < nNodes; i++ {
		iNode := DirectedGraphNodeID(nextInt())
		nAdjacent := nextInt()
		for j := 0; j < nAdjacent; j++ {
			jNode := DirectedGraphNodeID(nextInt())
			cost := nextInt()
			graph.setAdjacency(iNode, jNode, cost)
		}
	}

	graph.nodes[0].distance = 0
	for iNode := 0; iNode < nNodes; iNode++ {
		for iLeft := 0; iLeft < len(graph.nodes); iLeft++ {
			nodeLeft := graph.nodes[iLeft]
			for iRight := 0; iRight < len(nodeLeft.adjacents); iRight++ {
				nodeRight := nodeLeft.adjacents[iRight]
				cost := nodeLeft.costs[iRight]
				graph.relaxEdge(nodeLeft, nodeRight, cost)
			}
		}
	}

	// graph.print()

	for iNode := 0; iNode < len(graph.nodes); iNode++ {
		node := graph.nodes[iNode]
		fmt.Println(node.key, node.distance)
	}
}

C++: //さっさと済ませられるところはさっさと済ましてしまう．ただし注意深く
#include <cstdio>
#include <iostream>
#define MAX_VERTEXES 100
#define NIL -1
#define INFTY 20000000// >100*100000

using namespace std;

//think easy make easy

int n;//num of vertexes(頂点)
int matrix_graph[MAX_VERTEXES+1][MAX_VERTEXES+1];//0オリジン
bool vertex_set[MAX_VERTEXES+1];///0オリジン
int current_mincost[MAX_VERTEXES+1];//現時点での各頂点への最小コスト
bool candidate[MAX_VERTEXES+1];//次にvertex_setに加える頂点の候補
int new_vertex;

void findNextVertex(){
	int min_tmp=INFTY;
	int next_tmp = NIL;
	
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			if(i == new_vertex && vertex_set[j] == false){//わかりやすいプログラムほど処理もすくない.
				//無駄のないプログラムの方がわかりよい
				if(matrix_graph[i][j]+current_mincost[i] < current_mincost[j]
				   && matrix_graph[i][j] != NIL){
					   current_mincost[j]  = matrix_graph[i][j]+current_mincost[i];
					   candidate[j] = true;
				}
			}
		}
	}
	for(int i=0;i<n;i++){
		if(candidate[i] == true && current_mincost[i] < min_tmp){
			min_tmp = current_mincost[i];
			next_tmp = i;
		}
	}
	vertex_set[next_tmp] = true;
	candidate[next_tmp] = false;
	new_vertex = next_tmp;
}

int main(){
	scanf("%d",&n);

	int v_num;
	int k;//v_numの出次数

	for(int i=0;i<n;i++){
		for(int j=0;j<=n;j++){
			matrix_graph[i][j] = NIL;
		}
	}

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

		for(int j=0;j<k;j++){
			int v_num2;
			int cst;
			scanf("%d",&v_num2);
			scanf("%d",&cst);
			matrix_graph[v_num][v_num2] = cst;
		}
	}

	for(int i=0;i<n;i++){
		vertex_set[i] = false;
		current_mincost[i] = INFTY;
	}
	/*確認用
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			if(j<n-1) printf("%d ",matrix_graph[i][j]);
			else printf("%d\n",matrix_graph[i][j]);
		}
	}
	*/

	for(int i=0;i<n;i++){
		candidate[i] = false;
	}

	vertex_set[0] = true;
	current_mincost[0] = 0;
	new_vertex = 0;

	for(int i=1;i<n;i++){
		//for(int j=0;j<n;j++){
			//cout <<" " <<vertex_set[j] ;
		//}
		cout <<endl;
		findNextVertex();
	}


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


	return 0;
}

C++: #include<iostream>
#include<vector>
using namespace std;
const int MAX = 100;
const int INF = 200000;
int n, G[MAX][MAX];
int dis[MAX];
bool book[MAX] = { false };
void init()
{
	for (int i = 0; i < n; i++)
		dis[i] = G[0][i];
	book[0] = true;
}
void dijkstra()
{
	for (int k = 1; k <= n - 1; k++)
	{
		int min = INF;
		int u;
		for (int j = 0; j < n; j++)
			if (dis[j] > 0 && dis[j] < INF && !book[j] && dis[j] < min)
			{
				min = dis[j];
				u = j;
			}
		book[u] = true;
		for (int v = 0; v < n; v++)
			if (!book[v] && dis[u]+G[u][v] < dis[v])
				dis[v] = dis[u] + G[u][v];
	}
}
int main()
{
	cin >> n;
	for (int i = 0; i < n; i++)
		for (int j = 0; j < n; j++)
			if (i != j)
				G[i][j] = INF;
			else
				G[i][j] = 0;
	for (int i = 0; i < n; i++)
	{
		int u, d;
		cin >> u >> d;
		for (int j = 0; j < d; j++)
		{
			int v, w;
			cin >> v >> w;
			G[u][v] = w;
		}
	}
	init();
	dijkstra();
	for (int i = 0; i < n; i++)
		cout << i << " " << dis[i] << endl;
}

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

int INF = 900000000;
using pii = std::pair<int, int>;
std::vector<std::vector<pii>> g;
std::vector<bool> visited; 
std::vector<int> c; 
std::priority_queue<pii, std::vector<pii>, std::greater<pii>> q;

int n, p, x, y;
int discard;


int main() {
    std::cin >> n;
    visited.assign(n, false);
    g.assign(n, std::vector<pii>(0));
    c.assign(n, INF);
    for (int i = 0; i < n; i++) {
        std::cin >> discard >> p;
        for (int k = 0; k < p; k++) {
            std::cin >> x >> y;
            g[i].push_back(std::make_pair(y, x));
        }
    }
    q.push(std::make_pair(0, 0));
    c[0] = 0;
    while (!q.empty()) {
        auto e = q.top();
        q.pop();
        for (int j = 0; j < g[e.second].size(); j++) {
            if (c[g[e.second][j].second] < g[e.second][j].first) {
                continue;
            }
            if (c[e.second]+g[e.second][j].first < c[g[e.second][j].second]) {
                c[g[e.second][j].second] = c[e.second]+g[e.second][j].first;
                q.push(g[e.second][j]);
            }
        }
    }
    for (int i = 0; i < n; i++) {
        std::cout << i << " " << c[i] << std::endl;
    }
}

C++: #include <stdio.h>
#include <algorithm>
#include <string.h>
using namespace std;

#define M 10005
#define INF 0x3f3f3f3f

int d[M][M],a[M],n;
bool vis[M];

void dijkstra()
{
    printf("%d!\n",n);
    for(int i=0;i<n;i++){
        if(i == 0) a[i]=0;
        else a[i]=INF;
    }
    memset(vis,0,sizeof(vis));
    for(int i=0;i<n;i++){
        int mark=-1,minn=INF;
        for(int j=0;j<n;j++){
            if(!vis[j]&&a[j]<minn){
                minn=a[j];
                mark=j;
            }
        }
        vis[mark]=1;
        for(int j=0;j<n;j++){
            if(!vis[j]){
                a[j]=min(a[j],a[mark]+d[mark][j]);
            }
        }
    }
    for(int i=0;i<n;i++){
        printf("%d %d\n",i,a[i]);
    }
}

int main()
{
    scanf("%d",&n);
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            if(j == i)
                d[i][j]=0;
            else
                d[i][j]=INF;
        }
    }
    for(int j=0;j<n;j++){
        int u,k;
        scanf("%d%d",&u,&k);
        for(int i=0;i<k;i++){
            int v,w;
            scanf("%d%d",&v,&w);
            d[u][v]=w;
        }
    }
    dijkstra();
    return 0;
}