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<iostream>
#define MAX 100
#define MAXNUM 10000001
using namespace std;
int n, minv, M[MAX][MAX];
int w[MAX], color[MAX] = {};

void dijkstra() {
	for (int i = 0; i < n; i++) {
		w[i] = MAXNUM;
	}
	w[0] = 0;
	color[0] = 1;
	while (1) {
		minv = MAXNUM;
		int u = -1;
		for (int i = 0; i < n; i++) {
			if (w[i] < minv && color[i] != 2) {
				u = i;
				minv = w[i];
			}
		}
		if (u == -1) break;
		color[u] = 2;
		for (int i = 0; i < n; i++) {
			if (color[i] != 2 && M[u][i] != MAXNUM) {
				if (w[i] > w[u] + M[u][i]) {
					w[i] = w[u] + M[u][i];
					color[i] = 1;
				}
			}
		}
	}
}

int main() {
	int u, k, v, c;
	cin >> n;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			M[i][j] = MAXNUM;
		}
	}
	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();
	for (int i = 0; i < n; i++) {
		cout << i << " ";
		if (w[i] != MAXNUM) {
			cout << w[i] << endl;
		}
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
static const int MAX=100;
static const int INFTY=1000000000;
static const int WHITE=-1;
static const int BLACK=1;

int A[MAX][MAX],dk[MAX],p[MAX];

void SSSP(int n){
    int C[n];
    for(int i=0;i<n;i++){
        C[i]=WHITE;
        dk[i]=INFTY;
    }
    dk[0]=0;
    while(true){
        int u=-1;int minv=INFTY;
        for(int i=0;i<n;i++){
            if(C[i]==WHITE&&minv>dk[i]){
                minv=dk[i];
                u=i;
            }
        }
        if(u==-1)break;
        C[u]=BLACK;
        for(int i=0;i<n;i++){
            if(C[i]==WHITE&&A[u][i]!=INFTY){
                if(dk[i]>dk[u]+A[u][i]){
                    dk[i]=dk[u]+A[u][i];
                }
            }
        }
    }
}

int main(){
    int n,v,k,u,d;
    cin>>n;
    for(int i=0;i<n;i++)for(int j=0;j<n;j++)A[i][j]=INFTY;

    for(int i=0;i<n;i++){
        scanf("%d %d",&v,&k);
        for(int j=0;j<k;j++){
            scanf("%d %d",&u,&d);
            A[v][u]=d;
        }
    }
    SSSP(n);
    for(int i=0;i<n;i++){
        printf("%d %d\n",i,dk[i]);
    }

}

C++: #include <cstdio>
#include <map>
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;
map<int, int> *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 (map<int, int>::iterator it = M[u].begin(); it != M[u].end(); it++) {
            if (color[it->first] != BLACK) {
                if (d[u] + it->second < d[it->first]) {
                    d[it->first] = d[u] + it->second;
                    color[it->first] = GRAY;
                }
            }
        }
    }
    
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, d[i]);
    }
}

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

    M = new map<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);
            M[u][v] = c;
        }
    }

    dijkstra();

    return 0;
}

C++: #include <iostream>
#include <vector>
#include <string>
#include <bitset>
#include <cmath>
#include <queue>
#include <iomanip>
#include <algorithm>
#include <stack>
#include <cmath>
using namespace std;

#define INF 1e18
#define int long long
static const int MAX = 110;
static const int NOTFIXED = 0;
static const int FIXED = 1;

int n, m[MAX][MAX];

void dijkstra() {
    int d[n], status[n];
    for(int i = 0; i < n; i++) {
        d[i] = INF;
        status[i] = NOTFIXED;
    }
    d[0] = 0;
    status[0] = NOTFIXED;

    while(true) {
        int u = -1;
        int minv = INF;
        for(int i = 0; i < n; i++) {
            if(minv > d[i] && status[i] != FIXED) {
                u = i;
                minv = d[i];
            }
        }

        if(u == -1) break;
        status[u] = FIXED;
        for(int v = 0; v < n; v++) {
            if(m[u][v] != INF && status[v] != FIXED) {
                if(d[v] > d[u] + m[u][v]) {
                    d[v] = d[u] + m[u][v];
                    status[v] = NOTFIXED;
                }
            }
        }
    }

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

signed main() {
    cin >> n;

    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            m[i][j] = INF;
        }
    }

    for(int i = 0; i < n; i++) {
        int u, k; cin >> u >> k;
        for(int j = 0; j < k; j++) {
            int v, c; cin >> v >> c;
            m[u][v] = c;
        }
    }

    dijkstra();

    return 0;
}