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++: /*
 * Input
 * An edge-weighted graph G (V, E) and the source r.
 *
 * |V| |E| r
 * s0 t0 d0
 * s1 t1 d1
 * :
 * s|E|−1 t|E|−1 d|E|−1
 * |V| is the number of vertices and |E| is the number of edges in G. The graph
 * vertices are named with the numbers 0, 1,..., |V|−1 respectively. r is the
 * source of the graph.
 *
 * si and ti represent source and target vertices of i-th edge (directed) and di
 * represents the cost of the i-th edge.
 *
 * Output
 * c0
 * c1
 * :
 * c|V|−1
 * The output consists of |V| lines. Print the cost of the shortest path from
 * the source r to each vertex 0, 1, ... |V|−1 in order. If there is no path
 * from the source to a vertex, print INF.
 *
 * Constraints
 * 1 ≤ |V| ≤ 100000
 * 0 ≤ di ≤ 10000
 * 0 ≤ |E| ≤ 500000
 * There are no parallel edges
 * There are no self-loops
 */

#include <algorithm>
#include <iostream>
#include <map>
#include <queue>
#include <vector>
using namespace std;

int main() {
  int n, m, source = 0;
  cin >> n; // >> m >> source;
  vector<map<int, int>> adj(100000);

  vector<int> d(100000, 1000000001);
  bool visited[100000];
  int n_visited = 0;

  for (int u, k; cin >> u >> k;) {
    for (int i = 0, v, len; i < k; ++i) {
      cin >> v >> len;
      adj[u][v] = len;
    }
  }

  auto cmp = [&](int s, int t) { return d[s] > d[t]; };
  priority_queue<int, vector<int>, decltype(cmp)> q(cmp);

  d[source] = 0;
  q.push(source);
  while (!q.empty() and n_visited < n) {
    auto u = q.top();
    q.pop();
    if (visited[u])
      continue;
    ++n_visited;
    visited[u] = true;
    for (auto &kv : adj[u]) {
      d[kv.first] = min(d[kv.first], d[u] + kv.second);
      q.push(kv.first);
    }
  }

  for (int i = 0; i < n; ++i) {
    cout << i << " ";
    if (visited[i])
      cout << d[i];
    else
      cout << "INF";
    cout << endl;
  }
}

C++: #include<stdio.h>
#include<string.h>
long long arr[205][205];
long long min(long long a,long long b){
	return a>b?b:a;
}
int main() {
    int n,m;
    while(scanf("%d",&n)!=EOF){
    	long long x,y,c,d;
    	for(int i=0;i<205;i++){
    		for(int j=0;j<205;j++){
    		 arr[i][j]=10000000;	
			}
		}
    	for(int j=0;j<n;j++){
    	scanf("%lld %lld",&x,&y);
    	for(int h=0;h<y;h++){
    		scanf("%lld %lld",&c,&d);
    		arr[x][c]=min(arr[x][c],d);
		}
		}
	for(int k=0;k<n;k++){
		for(int i=0;i<n;i++){
			for(int j=0;j<n;j++){
				arr[i][j]=min(arr[i][j],arr[i][k]+arr[k][j]);
			}
		}
	}
	printf("0 0\n");
	for(int i=1;i<n;i++){
    printf("%d %lld\n",i,arr[0][i]);
   }
    }
	return 0;
}

C++: #include <iostream>
#include <queue>
#include <vector>
#include <utility>
using namespace std;
typedef pair<int, int> P;
struct edge {int to, cost;};
const int INF = (1 << 28);
int n;
vector<edge> G[110];


vector<int> dijkstra(int s) {
    priority_queue<P, vector<P>, greater<P>> que;
    que.push(P(0, s));
    vector<int> d(n, INF);
    d[s] = 0;
    while (!que.empty()) {
        P p = que.top(); que.pop();
        int v = p.second;
        if (d[v] < p.first) continue;
        for (auto e: G[v]) {
            if (d[e.to] > d[v] + e.cost) {
                d[e.to] = d[v] + e.cost;
                que.push(P(d[e.to], e.to));
            }
        }
    }
    return d;
}

int main(void) {
    cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k, v, c;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            cin >> v >> c;
            G[u].push_back(edge {v, c});
        }
    }
    vector<int> d = dijkstra(0);
    for (int i = 0; i < n; i++) {
        cout << i << " " << d[i] << endl;
    }

    return 0;
}

C++: #include<bits/stdc++.h>
#define INF 10000000
#define NIL -1
#define BLACK 2
#define WHITE 0
#define GRAY 1
#define MAX 100
using namespace std;

int color[MAX]={},d[MAX]={},pi[MAX]={},n;

void initializeSingleSource(int w[MAX][MAX]){
    for(int v=0;v<n;v++){
        d[v]=INF;
        pi[v]=NIL;
    }
    d[0]=0;
}

void relax(int u,int v,int w[MAX][MAX]){
    if(d[v]>d[u]+w[u][v]){
        d[v]=d[u]+w[u][v];
        pi[v]=u;
    }
}

void dijkstra(int w[MAX][MAX]){
    int mincost,i,v,u;
    initializeSingleSource(w);
    while(1){
        mincost=INF;
        u=NIL;
        for(i=0;i<n;i++){
            if(color[i]!=BLACK&&d[i]<mincost){
                mincost=d[i];
                u=i;
            }
        }
        if(u==NIL)break;
        color[u]=BLACK;
        for(v=0;v<n;v++){
            if(color[v]!=BLACK&&d[u]+w[u][v]<d[v]){
                pi[v]=u;
                d[v]=d[u]+w[u][v];
                color[v]=GRAY;
            }
        }
    }
}

void prim(int w[MAX][MAX]){
    int u,i,v,mincost,j;
    for(u=0;u<n;u++){
        d[u]=INF;
        pi[u]=NIL;
        color[u]=WHITE;
    }
    d[0]=0;
    while(1){
        mincost = INF;
        u=-1;
        for(i=0;i<n;i++){
            if(color[i]!=BLACK&&d[i]<mincost){
                mincost=d[i];
                u=i;
            }
        }
        if(u==-1)break;
        color[u]=BLACK;
        for(v=0;v<n;v++){
            if(color[v]!=BLACK&&w[u][v]!=INF){
                if(d[v]>w[u][v]){
                    pi[v]=u;
                    d[v]=w[u][v];
                    color[v]=GRAY;
                }
            }
        }
    }
    int sum=0;
    for(i=0;i<n;i++){
        if(pi[i]!=NIL)sum+=w[i][pi[i]];
    }

    for(i=0;i<n;i++){
        for(j=0;j<n;j++){
            cout<<w[i][j]<<" ";
        }
        cout<<endl;
    }

    cout<<endl;

    for(i=0;i<n;i++){
        cout<<pi[i]<<" ";
    }
    cout<<endl;
}

int main(){
    int w[MAX][MAX],i,j,id,k,weight,gow,ans;
    cin>>n;
    for(i=0;i<MAX;i++){
        for(j=0;j<MAX;j++){
            w[i][j]=INF;
        }
    }
    for(i=0;i<n;i++){
        cin>>id>>k;
        for(j=0;j<k;j++){
            cin>>gow>>weight;
            w[id][gow]=weight;
        }
    }
    dijkstra(w);
    for(i=0;i<n;i++){
        cout<<i<<" "<<d[i]<<endl;
    }
}