Go: package main

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

const BIG_COST = 200000

const (
	ST_NOT_YET = iota
	ST_JOINED
)

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	nNodes := scanInt(sc)

	costs := make([][]int, nNodes)
	graph := make([][]int, nNodes)

	states := make([]int, nNodes)
	costSums := make([]int, nNodes)

	for i := 0; i < nNodes; i++ {
		costs[i] = make([]int, nNodes)
		costSums[i] = BIG_COST
	}

	for i := 0; i < nNodes; i++ {
		u := scanInt(sc)
		k := scanInt(sc)
		graph[u] = make([]int, k)
		for d := 0; d < k; d++ {
			v := scanInt(sc)
			graph[u][d] = v
			costs[u][v] = scanInt(sc)
		}
	}

	costSums[0] = 0
	for {
		minCost := BIG_COST
		var u int

		for i, cost := range costSums {
			if states[i] != ST_JOINED && cost < minCost {
				minCost = cost
				u = i
			}
		}

		if minCost == BIG_COST {
			break
		}

		states[u] = ST_JOINED

		for _, v := range graph[u] {
			cost := minCost + costs[u][v]
			if cost < costSums[v] {
				costSums[v] = cost
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i, cost := range costSums {
		fmt.Fprintf(w, "%d %d\n", i, cost)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

C++: #include <cstdio>

const int N = 100;
const int INF = 100001;
int cost[N][N];
int minCost[N] = {0};
bool isDecide[N] = {false};

int getMinIndex(int n) {
        int minIndex = -1;
        int cost = INF;
        for (int i = 0; i < n; i++) {
                if (minCost[i] < cost && !isDecide[i]) {
                        cost = minCost[i];
                        minIndex = i;
                }
        }

        return minIndex;
}

int main() {
        for (int i = 0; i < N; i++) {
                for (int j = 0; j < N; j++) {
                        cost[i][j] = -1;
                }
        }
        for (int i = 1; i < N; i++) {
                minCost[i] = INF;
        }
        int n, u, k, v, c;

        scanf("%d", &n);
        for (int i = 0; i < n; i++) {
                scanf("%d %d", &u, &k);
                for (int j = 0; j < k; j++) {
                        scanf("%d %d", &v, &c);
                        cost[u][v] = c;
                }
        }
        while (true) {
                int from = getMinIndex(n);
                if (from < 0) {
                        break;
                }
                isDecide[from] = true;
                for (int to = 0; to < n; to++) {
                        if (cost[from][to] < 0 || isDecide[to]) {
                                continue;
                        }
                        int newCost = minCost[from] + cost[from][to];
                        if (newCost < minCost[to]) {
                                minCost[to] = newCost;
                        }
                }
        }
        for (int i = 0; i < n; i++) {
                printf("%d %d\n", i, minCost[i]);
        }

        return 0;
}

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;
}