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 <cstdio>
#include <queue>
#include <utility>
using namespace std;
static const int INFTY = (1 << 21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int, int>> adj[100];
int *d;

void dijkstra() {
    priority_queue<pair<int, int>> PQ;
    int d[n], color[n];

    for (int i = 0; i < n; i++) {
        d[i] = INFTY;
        color[n] = WHITE;
    }
    d[0] = 0;
    PQ.push(make_pair(0, 0));

    while (!PQ.empty()) {
        pair<int, int> f = PQ.top();
        PQ.pop();

        int u = f.second;
        color[u] = BLACK;

        if (d[u] < f.first * (-1)) { continue; }

        for (int j = 0; j < adj[u].size(); j++) {
            int v = adj[u][j].first;
            if (color[v] == BLACK) { continue; }
            if (d[u] + adj[u][j].second < d[v]) {
                d[v] = d[u] + adj[u][j].second;
                // printf("d[%d] = %d\n", v, d[v]);
                PQ.push(make_pair(d[v] * (-1), v));
                color[v] = GRAY;
            }
        }
    }
    
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, d[i]);
    }
}

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

    // adj = new vector<pair<int, int>>[n];

    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);
            adj[u].push_back(make_pair(v, c));
        }
    }

    dijkstra();

    return 0;
}

C++: //ALDS1_12_B:Single Source Shortest Path I
//C++
#include <iostream>
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];
void dijkstra(){
    int minv;
    int d[MAX],color[MAX];
    for(int i=0;i<n;i++){
        d[i]=INFTY;
        color[i]=WHITE;
    }
    d[0]=0;
    color[0]=GRAY;
    while(1){
        minv=INFTY;
        int u=-1;
        for(int i=0;i<n;i++){
            if(minv>d[i]&&color[i]!=BLACK){
                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[v]>d[u]+M[u][v]){
                    d[v]=d[u]+M[u][v];
                    color[v]=GRAY;
                }
            }
        }
    }
    for(int i=0;i<n;i++){
        cout<<i<<" "<<(d[i]==INFTY?-1:d[i])<<endl;
    }
}
int main(){
    cin>>n;
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            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<vector>
#include<stack>
#include<queue>
#include<list>
#include<string>
#include<cstring>
#include<cstdlib>
#include<cstdio>
#include<cmath>
using namespace std;

const int NIL = -1;
const int MAX = 1 << 21;

int M[101][101];
int color[101], d[101], p[101];

int main(void)
{
	int n, u, k, v, c, mincost;
	cin >> n;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			M[i][j] = MAX;
		}
	}
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v >> c;
			M[u][v] = c;
		}
	}
	for (int i = 0; i < n; i++) {
		color[i] = 0;
		d[i] = MAX;
	}
	d[0] = 0;
	p[0] = -1;
	while (1) {
		mincost = MAX;
		for (int i = 0; i < n; i++) {
			if (color[i] != 2 && d[i] < mincost) {
				mincost = d[i];
				u = i;
			}
		}
		if (mincost == MAX)
			break;
		color[u] = 2;
		for (int v = 0; v < n; v++) {
			if (color[v] != 2) {
				if (d[u]+M[u][v] < d[v]) {
					d[v] = M[u][v] + d[u];
					p[v] = u;
					color[v] = 1;
				}
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << " " << d[i] << endl;
	}
	return 0;
}