Go: package main

import (
	"strconv"
	"fmt"
	"bufio"
	"os"
)
const INF = 1 << 21
var scanner = bufio.NewScanner(os.Stdin)

func nextInt() int {
	scanner.Scan()
	i, e := strconv.Atoi(scanner.Text())
	if e != nil {
		panic(e)
	}
	return i
}


func main() {
	scanner.Split(bufio.ScanWords)
	n := nextInt()
	adj := make([][]int, n)
	for i := range adj {
		adj[i] = make([]int, n)
	}

	for i := 0;i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			v := nextInt()
			c := nextInt()
			adj[u][v] = c
		}
	}

	// for i := range adj {
	// 	fmt.Println(adj[i])
	// }

	dist := make([]int, n)
	prev := make([]int, n)
	visited := make([]bool, n)
	dijkstra := func(start int, size int) {
		for i := 0; i < size; i++ {
			dist[i] = INF
			prev[i] = -1
			visited[i] = false
		}
		dist[start] = 0
		for {
			u := -1
			tmp_min := INF
			for i := 0; i < size; i++ {
				if visited[i] == false && dist[i] < tmp_min {
					tmp_min = dist[i]
					u = i
				}
			}
			if u == -1 {
				break
			}
			visited[u] = true
			for i := 0; i < size; i++ {
				if adj[u][i] > 0 {
					w := adj[u][i]
					newlen := dist[u] + w
					if newlen < dist[i] {
						dist[i] = newlen
						prev[i] = u
					}
				}
			}
		}
	}
	dijkstra(0, n)
	for i, cost := range dist {
		fmt.Printf("%d %d\n", i, cost)
	}
}

C++: #include <iostream>
#include <algorithm>
#include <cmath>
#include <cstdio>
using namespace std;
#define MAX 10000000

int b[110];

int solve(int a[110][110], int n){
	b[0] = 0;
	for(int i = 0;i < n;i++)
		for(int j = 1;j < n;j++)
			if(a[i][j] != -1)b[j] = min(b[j], a[i][j]+b[i]);
	return 0;
}

int main(){
	int a[110][110], n;
	fill((int*)a, (int*)(a+110), -1);
	fill(b, b+110, MAX);
	cin >> n;
	for(int i = 0;i < n;i++){
		int u, k, c, d;
		cin >> u >> k;
		for(int j = 0;j < k;j++){
			cin >> c >> d;
			a[u][c] = d;
		}
	}
	
	
	
	for(int i = 0;i < n;i++)solve(a, n);
	for(int i = 0;i < n;i++){
		cout << i << " " << b[i] << endl;
	}
	
	return 0;
}
/*
5
0 3 2 3 3 1 1 2
1 2 0 2 3 4
2 3 0 3 3 1 4 1
3 4 2 1 0 1 1 4 4 3
4 2 2 1 3 3
*/

C++: #include <stdio.h>
#include <iostream>
#include <queue>
#include <list>
using namespace std;

class Node
{
private:
	list<int> next_node_list;
	list<int> next_weight_list;
public:
	Node();
	void AddNextNode(int id, int weight);
	void SetWeight(int weight);
	void DistributeWeight();
	int weight_from_0;
	bool check;
};

Node::Node()
{
	weight_from_0 = -1;
	check = false;
}

Node *Node_list;

struct GreatNode
{
	bool operator()(const Node *n1, const Node *n2) const;
};
bool GreatNode::operator()(const Node *n1, const Node *n2) const
{
	return n1->weight_from_0 > n2->weight_from_0;
}
priority_queue<Node*, vector<Node*>, GreatNode > que;

void Node::AddNextNode(int id, int weight)
{
	next_node_list.push_back(id);
	next_weight_list.push_back(weight);
}

void Node::SetWeight(int weight)
{
	if (weight_from_0 == -1 || weight < weight_from_0) {
		weight_from_0 = weight;
	}
}

void Node::DistributeWeight()
{
	check = true;
	list<int>::iterator itr2 = next_weight_list.begin();
	for(list<int>::iterator itr = next_node_list.begin(); itr != next_node_list.end(); itr++){	
		if (Node_list[*itr].check == false) {
			Node_list[*itr].SetWeight(weight_from_0 + *itr2);
			que.push(&Node_list[*itr]);
		}
		itr2++;
	}
	next_node_list.clear();
	next_weight_list.clear();
}

int main(void)
{
	//input
	int n;
	cin >> n;
	Node_list = new Node[n]();
	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;
			Node_list[i].AddNextNode(v, c);
		}
	}

	//weight from 0 ?
	Node_list[0].check = true;
	Node_list[0].weight_from_0 = 0;
	Node_list[0].DistributeWeight();
	while (!que.empty()) {
		Node *node = que.top();
		que.pop();
		node->DistributeWeight();
	}

	//output
	for (int i = 0; i < n; i++) {
		cout << i << " " << Node_list[i].weight_from_0 << endl;
	}
	
	return 0;
}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#define MAX_V 100
#define INF 1e9
using namespace std;
int cost[MAX_V][MAX_V];
int d[MAX_V];
bool used[MAX_V];
int V;
void dijkstra(int s) {
	for (int i = 0; i < V; i++) {
		d[i] = INF;
		used[i] = false;
	}
	d[s] = 0;
	while (true) {
		int v = -1;
		for (int u = 0; u < V; u++) {
			if (!used[u] && (v == -1) || d[u] < d[v]) {
				v = u;
			}
		}
		//全ての頂点が到達済み
		if (v == -1) {
			break;
		}
		//集合に新たに頂点を追加
		used[v] = true;
		for (int u = 0; u < V; u++) {
			d[u] = min(d[u], d[v] + cost[v][u]);
		}
	}
}

int main() {
	for (int i = 0; i < V; i++) {
		for (int j = 0; j < V; j++) {
			cost[i][j] = INF;
		}
	}
	cin >> V;
	for (int i = 0; i < V; i++) {
		int u;
		cin >> u;
		int k;
		cin >> k;
		for (int j = 0; j < k; j++) {
			int v;
			cin >> v;
			int c;
			cin >> c;
			cost[u][v] = c;
		}
	}
	dijkstra(0);

	for (int i = 0; i < V; i++) {
		cout << i << " " << d[i] << endl;
	}
	return 0;
}

C++: //Dijkstra
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<queue>
#include<vector>
using namespace std;
typedef pair<int, int> P;
int n, dis[101], n_left;
vector< vector<P> > G(101);
priority_queue< P, vector<P>, greater<P> > heap;
bool visited[101];

int main(){
    int u, v, k, w;

    scanf("%d", &n);
    n_left = n;
    for(int i=0; i<n; i++){
        scanf("%d %d", &u, &k);
        for(int j=0; j<k; j++){
            scanf("%d %d", &v, &w);
            G[u].push_back(P(w, v));
        }
    }
    memset(visited, 0, sizeof(visited));
    memset(dis, 127, sizeof(dis));

    dis[0] = 0;
    heap.push(P(0, 0));
    while(!heap.empty() && n_left>0){
        P top = heap.top();
        heap.pop();
        if(!visited[top.second]){
            u = top.second;
            visited[u] = true;
            --n_left;
            for(int i=0; i<G[u].size(); i++){
                v = G[u][i].second;
                w = dis[u] + G[u][i].first;
                if(!visited[v] && w < dis[v]){
                    heap.push(P(w, v));
                    dis[v] = w;
                }
            }
        }
    } 
    for(int i=0; i<n; i++){
        printf("%d %d\n", i, dis[i]);
    }
    return 0;
}

C++: #include <iostream>
using namespace std;

const int MAX_N = 100;
const int INF = (1 << 21);

int N;
int A[MAX_N][MAX_N];
int d[MAX_N], c[MAX_N];

void dj() {
  d[0] = c[0] = 0;

  while (1) {
    int cost = INF;
    int cur = -1;

    for (int i = 0; i < N; i ++) {
      if (c[i] != 1 && d[i] < cost) {
        cost = d[i];
        cur = i;
      }
    }

    if (cur == -1) break;
    c[cur] = 1;

    for (int v = 0; v < N; v++) {
      if (c[v] != 1 && A[cur][v] != INF) {
        if (d[cur] + A[cur][v] < d[v]) {
          d[v] = d[cur] + A[cur][v];
          c[v] = 0;
        }
      }
    }
  }

  for (int i = 0; i < N; i++)
    cout << i << ' ' << d[i] << endl;
}

int main() {
  cin >> N;
  for (int i = 0; i < N; i++) {
    for (int j = 0; j < N; j++)
      A[i][j] = INF;
    d[i] = INF;
    c[i] = -1;
  }

  for (int i = 0; i < N; i++) {
    int cur, k; cin >> cur >> k;

    for (int j = 0; j < k; j++) {
      int u, v;
      cin >> u >> v;
      A[cur][u] = v;
    }
  }

  dj();

  return 0;
}