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++: /*
 * 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;
}