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++: // 単一始点最短経路 ( ダイクストラ法 )
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<stack>
#include<algorithm>
#include<iostream>
#include<cmath>
#include<vector>

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];

int Dijkstra()
{
    int u, minv;
    int d[MAX], p[MAX], color[MAX];

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

    // 初期値の設定
    d[0] = 0;
    color[0] = GRAY;

    while(1)
    {
        minv = INFTY;
        // 次に移動するべき頂点
        u = -1;

        for(int i = 0; i < n; i++)
        {
            if( minv > d[i] && color[i] != BLACK )
            {
                // 未訪問の頂点の中で, 最小のコストを持つ辺を探索する
                u = i;
                minv = d[i];
            }
        }

        if( u == -1 )
        {
            // 最初全域木が完成した
            break;
        }

        color[u] = BLACK;

        for(int v = 0; v < n; v++)
        {
            if( color[v] != BLACK && M[u][v] != INFTY )
            {
                // u → v の辺の中で, 最小コストの辺のコストを記録する
                if( d[v] > d[u] + M[u][v] )
                {
                    // コストの記録
                    d[v] = d[u] + M[u][v];
                    // 頂点 v の親を記録する
                    p[v] = u;
                    // 訪問状態の記録
                    color[v] = GRAY;
                }
            }
        }
    }

    /*
    int sum = 0;

    for(int i = 0; i < n; i++)
    {
        if( p[i] != -1 )
        {
            // 最小コストの辺の和を求める
            sum += M[i][p[i]];
        }
    }
    */

    for(int i = 0; i < n; i++)
    {
        cout << i << " " << ( d[i] == INFTY ? -1 : d[i] ) << endl;
    }

    return 0;
}

int main(void)
{

    cin >> n;

    for(int i = 0; i < n; i++)
    {
        for(int j = 0; j < n; j++)
        {
            // 配列の初期化
            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 <iostream>
#include <algorithm>
#include <cmath>
#include <cstdio>
using namespace std;
#define MAX 10000000

int b[110];
struct edge{int from, to, cost;};

int solve(edge a[10010], int n, int nn){
	b[0] = 0;
	while(1){
		int update = 0;
		for(int i = 0;i < nn;i++){
			if(b[a[i].from] != MAX && b[a[i].to] > b[a[i].from] + a[i].cost){
				b[a[i].to] = b[a[i].from] + a[i].cost;
				update = 1;
			}
		}
		if(update == 0)break;
	}
	return 0;
}

int main(){
	int n, nn = 0;
	edge a[10010];
	fill(b, b+110, MAX);
	cin >> n;
	for(int i = 0;i < n;i++){
		int u, k, c, d;
		cin >> u >> k;
		for(int j = 0;j < k;j++){
			cin >> c >> d;
			a[nn].from = u;
			a[nn].to = c;
			a[nn++].cost = d;
		}
	}
	
	solve(a, n, nn);
	for(int i = 0;i < n;i++){
		cout << i << " " << b[i] << endl;
	}
	
	return 0;
}
/*
5
0 3 2 3 3 1 1 2
1 2 0 2 3 4
2 3 0 3 3 1 4 1
3 4 2 1 0 1 1 4 4 3
4 2 2 1 3 3
*/