Go: package main

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

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := make(map[int]int)
	q[0] = 0
	visited := make(map[int]struct{})
	out := make([]int, n)

	for len(q) > 0 {
		u := top(q)
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			if d, ok := q[uu]; !ok || d > q[u]+c {
				q[uu] = q[u] + c
			}
		}

		out[u] = q[u]
		delete(q, u)
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

func top(q map[int]int) int {
	minu := -1
	min := -1
	for u, d := range q {
		if min < 0 || d < min {
			minu = u
			min = d
		}
	}

	return minu
}

C++: #include<iostream>
#include<cstdio>
#include<cstring>
#define INF 9999
using namespace std;
int n;
int A[1000][1000];
int d[1000];
bool used[1000];
int D[1000][1000];
 
void Init(int f){
  for(int i=0;i<f;i++){
    for(int j=0;j<f;j++)D[i][j] = INF;
  }
 
}
 
int main(){
  scanf("%d",&n);
  int u,k,C,V;
  Init(n);
  
  for(int i=0;i<n;i++){
      scanf("%d %d",&u,&k);     
      for(int j=0;j<k;j++){
    scanf("%d %d",&V,&C);
    D[u][V] = C;
    D[V][u] = C;
      }     
  }
   
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = min(D[i][j],D[i][k] + D[k][j]); 
  for(int i=0;i<n;i++){
    printf("%d %d\n",i,D[0][i]);
  }
 
  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;
                }
            }
        }
    }
    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 <cstdio>
#include <vector>

int main(void){

	int n, count, next_node, num_neighbors, min_distance;
	std::vector< std::vector<int> > edges;
	std::vector< std::vector<int> > neighbors;
	std::vector<bool> isUsed;
	std::vector<int> distance;
	scanf("%d", &n);
	edges.resize(n);
	isUsed.resize(n);
	neighbors.resize(n);
	distance.resize(n);
	for(int i=0;i<n;i++){
		scanf("%d %d", &next_node, &num_neighbors);
		edges[next_node].resize(num_neighbors);
		neighbors[next_node].resize(num_neighbors);
		for (int j=0;j<num_neighbors;j++){
			scanf("%d %d", &neighbors[next_node][j], &edges[next_node][j]);
		}
		isUsed[next_node]=-false;
		distance[next_node]=-1;
	}
	isUsed[0] = true;
	distance[0] = 0;
	count=0;
	for(int i=0;i<neighbors[0].size();i++){
		distance[neighbors[0][i]] = edges[0][i];
	}
	int neighbor;
	while(count<n-1){
		min_distance = 100000;
		for(int i=0;i<n;i++){
			if(!isUsed[i] && distance[i] != -1 && distance[i]<min_distance){
				next_node = i;
				min_distance = distance[i];
			}
		}
		isUsed[next_node] = true;
		for(int i=0;i<neighbors[next_node].size();i++){
			neighbor = neighbors[next_node][i];
			if(distance[neighbor] > distance[next_node]+edges[next_node][i] || distance[neighbor] <0){
				distance[neighbor] = distance[next_node] + edges[next_node][i];
			}
		}
		count ++;
	}
	for(int i=0;i<n;i++){
		printf("%d %d\n", i, distance[i]);
	}
	return 0;
}

C++: #include <iostream>
#include <utility>
#include <vector>
#include <queue>
using namespace std;
#define INF 2400000000
long long int Min(long long int x,long long int y){
        return x>y?y:x;
}
int main(){
        int N;
        cin >> N;
        vector <vector <long long int> > adjancent(N,vector <long long int>(N,INF));
        for(int i=0 ; i<N ; i++ ){
                int n,degree,to,cost;
                cin >> n >> degree;
                for(int l=0 ; l<degree ; l++ ){
                        cin >> to >> cost;
                        adjancent[n][to]=cost;
                }
        }
        vector<long long int> dp(N,INF);
        dp[0]=0;
        bool sign=true;
        while(sign){
                sign=false;
                for(int now=0 ; now<N ; now++){
                        for(int i=0 ; i<N ; i++ ){
                                int tmp=dp[i];
                                dp[i]=Min(dp[i],dp[now]+adjancent[now][i]);
                                if(tmp!=dp[i])
                                        sign=true;
                        }
                }
        }
        for(int i=0 ; i<N ; i++ )
                cout <<i<<" "<<dp[i]<<endl;
        return 0;
}

C++: #include<iostream>
#include<vector>
#include<map>
#include<set>
#include<tuple>
#include<queue>
using namespace std;
#define int long long
vector<double> dijk(vector<tuple<int,int,double>> edge_list, int start){
        const int DJMAX = 100000;
        set<int> node_list;
        for(auto edge : edge_list){
                node_list.insert(get<0>(edge));
                node_list.insert(get<1>(edge));
        }
        int nodenum = *node_list.rbegin()+1;
        vector<vector<double>> cost_map(nodenum, vector<double>(nodenum, DJMAX));
        for(auto edge : edge_list){
                cost_map[get<0>(edge)][get<1>(edge)] = get<2>(edge);
                cost_map[get<1>(edge)][get<0>(edge)] = get<2>(edge);
        }
        vector<double> cost(nodenum,DJMAX);
        cost[start] = 0;
        vector<int> visited(nodenum,0);
        priority_queue<pair<int,int>> que;
        que.push(pair<double,int>(0,start));
        while(!que.empty()){
                int s = que.top().second;
                que.pop();
                visited[s] = 1;
                for(int j=0;j<nodenum;j++){
                        if(visited[j]==1) continue;
                        double nc = cost[s]+cost_map[s][j];
                        if(nc<cost[j]){
                                cost[j] = nc;
                                que.push(pair<double,int>(-cost[j],j));
                        }
                }
        }
        return cost;
}
signed main(){
        int n;
        cin >> n;
        vector<tuple<int, int, double>> edges;
        for(int i=0;i<n;i++){
                int vs, vn;
                cin >> vs >> vn;
                for(int j=0;j<vn;j++){
                        int vt,c;
                        cin >> vt >> c;
                        edges.push_back(tuple<int,int,double>(vs,vt,c));
                }
        }
        auto ans = dijk(edges, 0);
        for(int i=0;i<n;i++){
                cout << i << " " << ans[i] << endl;
        }
        return 0;
}