Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Node struct {
	cost int
	done bool
}

type Edge struct {
	to, cost int
}

const INF = 1 << 60

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	nodes := make([]Node, N)
	for i := 0; i < N; i++ {
		nodes[i].cost = INF
	}
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id] = append(E[id], Edge{to, cost})
		}
	}
	nodes[0].cost = 0
	for {
		cur := 0
		minCost := INF
		for i := 0; i < N; i++ {
			n := nodes[i]
			if !n.done && n.cost < minCost {
				cur = i
				minCost = n.cost
			}
		}
		if minCost == INF {
			break
		}
		nodes[cur].done = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+nodes[cur].cost
			if !nodes[to].done && cost < nodes[to].cost {
				nodes[to].cost = cost
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, nodes[i].cost)
	}
	wtr.Flush()
}

C++: #include<stdio.h>
#include<cstdlib>
// 0origin
// referred to http://www.deqnotes.net/acmicpc/dijkstra/
// 単純な方法の方

#define MAX_DATA 100
#define INF 1000001
#define NIL -2

int n;
typedef struct {
    int num;
    // ここから伸びるエッジの情報
    int edges_to[MAX_DATA]; // 各接続先の番号
    int edges_cost[MAX_DATA]; // 各エッジのコスト
    int edges_size; // エッジの本数
    
    // ダイクストラ法のためのデータ
    bool done; // 確定ノードか否か
    int cost; // このノードへの現時点で判明しているコスト
}Node;

Node node[MAX_DATA];

int min(int x, int y){
    return x < y ? x : y;
}

void Init(){
    for (int i = 0; i < n; i++) {
        node[i].done = false;
        node[i].cost = INF;
    }
}

void Dijkstra(){
    Init();
    node[0].cost = 0;
    /*
    while (1) {
        Node doneNode;
        doneNode.cost = NIL;
        for (int i = 0; i < n; i++) {
            printf("node[%d].done:%s cost:%d doneNode.cost:%d\n", i, node[i].done == true ? "true" : "false", node[i].cost, doneNode.cost);
            if (node[i].done == true || node[i].cost == INF) {
                continue;
            }
            if (doneNode.cost == NIL || node[i].cost < doneNode.cost) {
                doneNode = node[i];
            }
        }
        if(doneNode.cost == NIL){
            break;
        }
        
        .done = true;
        
        for (int i = 0; i < doneNode.edges_size; i++) {
            int to = doneNode.edges_to[i];
            int cost = doneNode.cost + doneNode.edges_cost[i];
            if (node[to].cost < 0 || cost < node[to].cost) {
                node[to].cost = cost;
            }
        }
    }*/
    
    Node doneNode[MAX_DATA];
    node[0].done = true;
    doneNode[0] = node[0];
    int NOFdoneNode = 1;
    while (NOFdoneNode < n) {
        int mincost = INF;
        for(int i = 0; i < NOFdoneNode; i++){ // doneNodeを動かす
            for(int j = 0; j < doneNode[i].edges_size; j++){ // doneNodeから伸びているnodeをうごかす
                //printf("%d to %d\n", doneNode[i].num, doneNode[i].edges_to[j]);
                if (node[doneNode[i].edges_to[j]].done) { // 確定ノードと確定ノードがつながっていたらスルー
                    //printf(" through\n");
                    continue;
                }
                //printf(" %d >?< %d\n", node[doneNode[i].edges_to[j]].cost, doneNode[i].cost + doneNode[i].edges_cost[j]);
                if(node[doneNode[i].edges_to[j]].cost >= doneNode[i].cost + doneNode[i].edges_cost[j]){ // 確定nodeたちからの最短距離を記録
                    node[doneNode[i].edges_to[j]].cost = doneNode[i].cost + doneNode[i].edges_cost[j];
                    if(mincost > node[doneNode[i].edges_to[j]].cost){ // mincostが更新されたらdoneNodeの最後尾を更新
                        mincost = node[doneNode[i].edges_to[j]].cost;
                        doneNode[NOFdoneNode] = node[doneNode[i].edges_to[j]];
                    }
                }
            }
        }
        node[doneNode[NOFdoneNode].num].done = true;
        //printf("%d is done\n", doneNode[NOFdoneNode].num);
        
        /*for(int i = 0; i < NOFdoneNode+1; i++){
            printf("%d,", doneNode[i].num);
        }
        printf("\n\n");*/
        NOFdoneNode++;
    }
}

int main(){
    int m;
    
    scanf("%d", &n);
    
    for(int i = 0; i < n; i++){
        scanf("%d%d", &m ,&m);
        node[i].edges_size = m;
        node[i].num = i;
        for (int j = 0; j < m; j++) {
            scanf("%d %d", &node[i].edges_to[j], &node[i].edges_cost[j]);
        }
        node[i].edges_to[m] = NIL;
        node[i].edges_cost[m] = NIL;
    }
    
#ifdef D
    for (int i = 0; i < n; i++) {
        printf("%d:", i);
        for (int j = 0; ; j++) {
            if(node[i].edges_to[j] == NIL){
                break;
            }
            printf("%d(%d) ", node[i].edges_to[j], node[i].edges_cost[j]);
        }
        printf("\n");
    }
#endif
    
    Dijkstra();
    
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, node[i].cost);
    }
    
    return 0;
}

C++: #include <iostream>
#include <limits>

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)

constexpr int MAXN = 100;
constexpr int MAXINT = std::numeric_limits<int>::max();


int G[MAXN][MAXN];
int D[MAXN];
int C[MAXN];
int P[MAXN];
int n;

int main() {
    std::cin >> n;
    FOR(i, 0, n)
    FOR(j, 0, n)
    {
        G[i][j] = MAXINT;
    }

    FOR(i, 0, n){
        int id, e;
        std::cin >> id >> e;
        FOR(i, 0, e) {
            int v, c;
            std::cin >> v >> c;
            G[id][v] = c;
        }
    }

    FOR(i, 0, n) D[i] = MAXINT;

    int r = -1;
    D[0] = 0;
    while (true) {
        int mincost = MAXINT;
        int t;
        for (int i = 0; i < n; i++) {
            if ((C[i] == 0)  && (D[i] < mincost)) {
                mincost = D[i];
                t = i;
            }
        }

        if (mincost == MAXINT) {
            break;
        }

        C[t] = 1;
        P[t] = r;

        for (int i = 0; i < n; i++) {
            if ((C[i] == 0) && (G[t][i] != MAXINT) && ((D[t] + G[t][i]) < D[i])) {
                D[i] = D[t] + G[t][i];
            }
        }
        r = t;
    }
    FOR(i, 0, n) {
        std::cout << i << " " << D[i] << std::endl;
    }
}