Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type DirectedGraphNodeID int

type DirectedGraphNode struct {
	key         DirectedGraphNodeID
	adjacents   []*DirectedGraphNode
	costs       []int
	distance    int
	predecessor *DirectedGraphNode
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for i := 0; i < nNodes; i++ {
		node := DirectedGraphNode{}
		node.key = DirectedGraphNodeID(i)
		node.distance = infty
		graph.nodes[i] = &node
	}
	return &graph
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(i, j DirectedGraphNodeID, cost int) {
	g.nodes[i].adjacents = append(g.nodes[i].adjacents, g.nodes[j])
	g.nodes[i].costs = append(g.nodes[i].costs, cost)
}

func (g *DirectedGraph) print() {
	for i := 0; i < len(g.nodes); i++ {
		node := g.nodes[i]
		key := node.key
		strings := []string{strconv.Itoa(int(key)), strconv.Itoa(node.distance)}
		for j := 0; j < len(node.adjacents); j++ {
			nodeJ := fmt.Sprintf("(%v, %v)", node.adjacents[j].key, node.costs[j])
			strings = append(strings, nodeJ)
		}
		fmt.Printf("%v\n", strings)
	}
}

func (g *DirectedGraph) relaxEdge(l, r *DirectedGraphNode, w int) {
	if r.distance > l.distance+w {
		// fmt.Printf("%v -> %v, %v\n", l.key, r.key, l.distance+w)
		r.distance = l.distance + w
		r.predecessor = l
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	graph := newDirectedGraph(nNodes)

	for i := 0; i < nNodes; i++ {
		iNode := DirectedGraphNodeID(nextInt())
		nAdjacent := nextInt()
		for j := 0; j < nAdjacent; j++ {
			jNode := DirectedGraphNodeID(nextInt())
			cost := nextInt()
			graph.setAdjacency(iNode, jNode, cost)
		}
	}

	graph.nodes[0].distance = 0
	for iNode := 0; iNode < nNodes; iNode++ {
		for iLeft := 0; iLeft < len(graph.nodes); iLeft++ {
			nodeLeft := graph.nodes[iLeft]
			for iRight := 0; iRight < len(nodeLeft.adjacents); iRight++ {
				nodeRight := nodeLeft.adjacents[iRight]
				cost := nodeLeft.costs[iRight]
				graph.relaxEdge(nodeLeft, nodeRight, cost)
			}
		}
	}

	// graph.print()

	for iNode := 0; iNode < len(graph.nodes); iNode++ {
		node := graph.nodes[iNode]
		fmt.Println(node.key, node.distance)
	}
}

C++: #include <cstdio>
#include <algorithm>
#include <queue>
using namespace std;
static const int INFTY = (1 << 20);
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++: #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;
    //d?????????????¨??????????????????¨????§????????????????????????????
    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(true){
        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(int argc, const char * argv[]) {
    int n;
    cin >> n;
    
    for(int i=0;i<n;i++)
        for(int j=0;j<n;j++)
            M[i][j] = INFTY;
    
    int u,k,v,c;
    
    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++: #define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
using namespace std;
const int INF = 2000000000;
const int num = 100;
int n, u, k, v, w;
int m[num][num];
int d[num];
int c[num];
int main() {
	cin >> n;
	fill(m[0], m[num], INF);
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v >> w;
			m[u][v] = w;
		}
	}
	fill(d, d + num, INF);
	fill(c, c + num, 0);
	d[0] = 0;
	while (true) {
		int ne = -1;
		int minv = INF;
		for (int i = 0; i < n; i++)
			if (!c[i] && d[i] < minv) {
				ne = i;
				minv = d[i];
			}
		if (ne == -1) break;
		c[ne] = 1;
		for (int i = 0; i < n; i++) {
			if (d[i] > d[ne] + m[ne][i]) d[i] = d[ne] + m[ne][i];
		}
	}
	for (int i = 0; i < n; i++)
		cout << i << " "<< d[i] << endl;
	return 0;
}

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;
        }
       }
     }
  }
    if(u == -1) break;
    color[u] = BLACK;
   for(int v = 0; v < n; v++){
    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,v,c,u;
 for(int i = 0;i < n; i++){
  cin >> u >>c;
  M[u][v] = c;
  }
 }
  dijkstra();
   return 0;
}