Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)

	g := makeGraph(n)
	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			c := getNextInt(scanner)
			g[u][v] = c
		}
	}

	ans := make([]int, n)
	im := make(IntMap, 1)
	im.increment(0)
	for len(im) < n {
		min := 1 << 30
		x := -1
		for u := range im {
			for v := 0; v < n; v++ {
				if im.get(v) != 0 {
					continue
				}
				if min > ans[u]+g[u][v] {
					min = ans[u] + g[u][v]
					x = v
				}
			}
		}
		im.increment(x)
		ans[x] = min
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i, ans[i]))
	}
	writer.Flush()
}

func makeGraph(n int) [][]int {
	g := make([][]int, n)
	for i := 0; i < n; i++ {
		g[i] = make([]int, n)
		for ii := 0; ii < n; ii++ {
			g[i][ii] = 1 << 30
		}
	}

	return g
}

// IntMap ...
type IntMap map[int]int

func (m IntMap) get(key int) int {
	if _, ok := m[key]; ok {
		return m[key]
	}
	return 0
}
func (m IntMap) increment(key int) {
	if _, ok := m[key]; ok == false {
		m[key] = 0
	}
	m[key]++
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include <cstdio>
#include <cstdlib>
#include <string>
#include <iostream>
#include <climits>
#include <list>
#include <queue>

using namespace std;

static const int INFTY = -1;

int H;
int A[101];
int NodeNum[101];
int IndexInA[100];


int parent(int i) {
	return i / 2;
}

int left(int i) {
	return 2 * i;
}

int right(int i) {
	return 2 * i + 1;
}

void minHeapify(int i) {
	int l = left(i);
	int r = right(i);
	int smallest = i;
	if (l <= H && A[l] < A[i]) {
		smallest = l;
	}
	if (r <= H && A[r] < A[smallest]) {
		smallest = r;
	}
	if (smallest != i) {
		int temp = A[i];
		A[i] = A[smallest];
		A[smallest] = temp;
		temp = NodeNum[i];
		NodeNum[i] = NodeNum[smallest];
		NodeNum[smallest] = temp;
		IndexInA[NodeNum[i]] = i;
		IndexInA[NodeNum[smallest]] = smallest;

		minHeapify(smallest);
	}
}

void insert(int d, int nodeNum) {
	int i = ++H;
	A[i] = d;
	NodeNum[i] = nodeNum;
	IndexInA[nodeNum] = i;
	int p = parent(i);
	while (i > 1 && A[p] > A[i]) {
		int temp = A[p];
		A[p] = A[i];
		A[i] = temp;
		temp = NodeNum[p];
		NodeNum[p] = NodeNum[i];
		NodeNum[i] = temp;
		IndexInA[NodeNum[p]] = p;
		IndexInA[NodeNum[i]] = i;
		i = p;
		p = parent(i);
	}
}

int heapExtractMinNodeNum() {
	int minNodeNum = NodeNum[1];
	A[1] = A[H];
	NodeNum[1] = NodeNum[H];
	IndexInA[NodeNum[1]] = 1;
	H--;
	minHeapify(1);

	return minNodeNum;
}

void decrese(int i, int value) {
	A[i] = value;
	int p = parent(i);
	while (i > 1 && A[p] > A[i]) {
		int temp = A[p];
		A[p] = A[i];
		A[i] = temp;
		temp = NodeNum[p];
		NodeNum[p] = NodeNum[i];
		NodeNum[i] = temp;
		IndexInA[NodeNum[p]] = p;
		IndexInA[NodeNum[i]] = i;
		i = p;
		p = parent(i);
	}
}

int main() {
	int Dist[100];
	int AdjacenceyList[100][100];
	int AdjacenceyWeightList[100][100];
	int Degree[100];
	int i, j;
	int N;
	int W;
	//int Deg;
	int MinTotalWeight = 0;
	int u, v;
	int k;
	bool inT[100];

	cin >> N;

	//for (i = 0; i < N; i++) {
	//	inT[i] = false;
	//	Dist[i] = INFTY;
	//	Deg = -1;
	//	for (j = 0; j < N; j++) {
	//		cin >> W;
	//		if (W != -1) {
	//			AdjacenceyList[i][++Deg] = j;
	//			AdjacenceyWeightList[i][Deg] = W;
	//		}
	//	}
	//	Degree[i] = Deg + 1;
	//}

	for (i = 0; i < N; i++) {
		inT[i] = false;
		Dist[i] = INFTY;
		cin >> u >> k;
		Degree[u] = k;
		for (j = 0; j < k; j++) {
			cin >> AdjacenceyList[u][j] >> AdjacenceyWeightList[u][j];
		}
	}


	H = 0;
	u = 0;
	inT[u] = true;
	Dist[u] = 0;
	for (i = 1; i <= N - 1; i++) {
		for (j = 0; j < Degree[u]; j++) {
			v = AdjacenceyList[u][j];
			if (inT[v] == false) {
				W = AdjacenceyWeightList[u][j];
				if (Dist[v] == INFTY) {
					//Dist[v] = W;
					//insert(W, v);
					Dist[v] = Dist[u] + W;
					insert(Dist[v], v);
				}
				//else if (W < Dist[v]) {
				else if(W + Dist[u] < Dist[v]){
					//Dist[v] = W;
					//decrese(IndexInA[v], W);
					Dist[v] = W + Dist[u];
					decrese(IndexInA[v], Dist[v]);
				}
			}
		}

		int minNodeNum = heapExtractMinNodeNum();
		inT[minNodeNum] = true;
		//MinTotalWeight += Dist[minNodeNum];
		u = minNodeNum;

	}

	//printf("%d\n", MinTotalWeight);

	for (i = 0; i < N; i++) {
		printf("%d %d\n", i, Dist[i]);
	}

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
vector<int> color;//0:白1:灰2:黒
vector<vector<int>> M;
vector<int> d;
vector<int> p;
typedef long long int Int;

const int INF = 10000000;
int n;
void dijkstra(int s){
    
    for(int i=0;i<n;i++){
        d[i] = INF;
    }
    d[s] = 0;
    p[s] = -1;

    while(1){
        int u=-1;
        int mincost = INF;
        for(int i=0;i<n;i++){
            if(color[i]!=2&&d[i]<mincost){
                mincost = d[i];
                u = i;
            }
        }
        if(mincost == INF) break;
        color[u] = 2;
        for(int v=0;v<n;v++){
            if(color[v]!=2&&M[u][v]!=INF){
                if(d[u]+M[u][v]<d[v]){
                    d[v] = d[u]+M[u][v];
                    p[v] = u;
                    color[v] = 1;
                }
            }
        }
    }
}

int main(){
    cin >> n;
    color.assign(n,0);//0:白1:灰2:黒
    M.assign(n,vector<int>(n,INF));
    d.resize(n);
    p.resize(n);
    for(int i=0;i<n;i++){
        int id,k;cin >> id >> k;
        for(int j=0;j<k;j++){
            int v,cost;cin >> v >> cost;
            M[id][v] = cost;
        }
    }
    dijkstra(0);
    for(int i=0;i<n;i++){
        cout << i << " ";
        cout << d[i] << endl;
    }
}

C++: #include <cstdio>
static const int INFTY = (1 << 21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n, **M;
int *d;

void dijkstra() {
    int u, minv;
    int d[n], color[n];

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

    while (1) {
        u = -1;
        minv = INFTY;
        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[u] + M[u][v] < d[v]) {
                    d[v] = d[u] + M[u][v];
                    color[v] = GRAY;
                }             
            }
        }
    }
    
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, d[i]);
    }
}

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

    M = new int*[n];
    for (int i = 0; i < n; i++) {
        M[i] = new int[n];
        for (int j = 0; j < n; j++) {
            M[i][j] = INFTY;
        }
    }

    for (int i = 0; i < n; i++) {
        int u, k;
        scanf("%d %d", &u, &k);
        for (int j = 0; j < k; j++) {
            int v, c;
            scanf("%d %d", &v, &c);
            M[u][v] = c;
        }
    }

    dijkstra();

    return 0;
}