Go: package main

import (
	"bufio"
	"container/heap"
	"fmt"
	"os"
	"strconv"
)

//make priority queue
type Item struct {
	id       int
	priority int // this state is priority and distans from start
	index    int
}

type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }

// we want the ascending-priority-queue.
// So we use less than here.
func (pq PriorityQueue) Less(i, j int) bool {
	return pq[i].priority < pq[j].priority
}

func (pq PriorityQueue) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
	pq[i].index = j
	pq[j].index = i
}

func (pq *PriorityQueue) Push(x interface{}) {
	n := len(*pq)
	item := x.(*Item)
	item.index = n
	*pq = append(*pq, item)
}

func (pq *PriorityQueue) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	item.index = -1 //for safety
	*pq = old[0 : n-1]
	return item
}

func (pq *PriorityQueue) update(dist int, id int) {
	for _, i := range *pq {
		if i.id == id {
			if i.priority > dist {
				i.priority = dist
			}
		}
	}
}

// the main code
func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	n, _ := strconv.Atoi(sc.Text())
	return n
}

func dikstra(dist [][]int, n int) []int {
	// preparate priority queue
	inf := 1 << 30
	pq := make(PriorityQueue, n)
	shortests := make([]int, n)
	for i := 0; i < n; i++ {
		pq[i] = &Item{
			id:       i,
			priority: inf,
			index:    i,
		}

		shortests[i] = inf
	}
	pq[0].priority = 0
	shortests[0] = 0
	heap.Init(&pq)

	for pq.Len() > 0 {
		item := heap.Pop(&pq).(*Item)
		shortests[item.id] = item.priority
		for id, d := range dist[item.id] {
			if d != -1 {
				pq.update(item.priority+d, id)
			}
		}
		heap.Init(&pq)
	}
	return shortests
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	// init
	n := nextInt(sc)
	dist := make([][]int, n)
	for i := 0; i < n; i++ {
		dist[i] = make([]int, n)
		for j := 0; j < n; j++ {
			dist[i][j] = -1
		}
	}

	// std Input
	for i := 0; i < n; i++ {
		u := nextInt(sc)
		k := nextInt(sc)
		for j := 0; j < k; j++ {
			v, c := nextInt(sc), nextInt(sc)
			dist[u][v] = c
		}
	}

	shortests := dikstra(dist, n)
	for i, d := range shortests {
		fmt.Printf("%d %d\n", i, d)
	}
}

Python: from heapq import heappush,heappop,heapify

n = int(input())
G = [[] for _ in range(n)]
info = []

for i in range(n):
    info =  list(map(int,(input().split())))[2:]
    for j in range(int((len(info))/2)):
        G[i].append((info[2*j],info[2*j+1]))

color = ["white" for _ in range(n)]
dist = [(1<<21) for _ in range(n)]
que = []

def dijkstra():
    dist[0] = 0
    que.append((0,0)) #(dist,node)
    while que:
        heapify(que)
        u = que.pop()[1]
        # print(u)
        color[u] = "black"
        for j in range(len(G[u])):
            if dist[u] + G[u][j][1] < dist[G[u][j][0]]:
                heappush(que,(dist[u] + G[u][j][1],G[u][j][0]))
                dist[G[u][j][0]] = dist[u] + G[u][j][1]

# for i in range(n):
#     print(*G[i])

dijkstra()

for i,dist in enumerate(dist):
    print(i,dist)

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
input:
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

output:
0 0
1 2
2 2
3 1
4 3
"""

import sys
import heapq as hp

WHITE, GRAY, BLACK = 0, 1, 2
D_MAX = int(1e7 + 1)


def generate_adj_matrix(v_info):
    for v_detail in v_info:
        v_index = int(v_detail[0])
        v_adj_length = int(v_detail[1])
        v_adj_list = v_detail[2:]
        # assert len(v_adj_list) == v_adj_length * 2
        for j in range(0, v_adj_length * 2, 2):
            init_adj_matrix[v_index][int(v_adj_list[j])] = int(v_adj_list[j + 1])

    return init_adj_matrix


def dijkstra_path():
    # path search init
    start_vertex_index = 0
    path_list[start_vertex_index] = 0
    path_heap = []
    # heapq: compare by tuple[0]
    hp.heappush(path_heap, (path_list[start_vertex_index], start_vertex_index))
    while len(path_heap) >= 1:
        current_vertex_index = hp.heappop(path_heap)[1]

        color[current_vertex_index] = BLACK

        for adj_vertex_index in range(vertices_num):
            current_adj_weight = adj_matrix[current_vertex_index].get(adj_vertex_index, -1)
            if current_adj_weight < 0:
                continue
            elif color[adj_vertex_index] is not BLACK:
                # d[u] + w[u,v]
                alt_path = path_list[current_vertex_index] + current_adj_weight
                if alt_path < path_list[adj_vertex_index]:
                    # update path_list
                    path_list[adj_vertex_index] = alt_path
                    # update heap
                    hp.heappush(path_heap, (alt_path, adj_vertex_index))
                    parent_list[adj_vertex_index] = current_vertex_index
                    color[adj_vertex_index] = GRAY

    return path_list


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    vertices_num = int(_input[0])
    init_vertices_table = list(map(lambda x: x.split(), _input[1:]))
    # assert len(init_vertices_table) == vertices_num

    parent_list, path_list = [-1] * vertices_num, [D_MAX] * vertices_num
    color = [WHITE] * vertices_num
    init_adj_matrix = tuple(dict() for _ in range(vertices_num))
    adj_matrix = generate_adj_matrix(init_vertices_table)
    ans = dijkstra_path()
    for i, v in enumerate(ans):
        print(i, v)

Python: # coding: utf-8
import queue
nodelist={}
n=int(input())
dist={}
used={}
for i in range(n):
    line=list(map(int,input().split()))
    nodelist[line[0]]=[]
    dist[line[0]]=99999999
    used[line[0]]=False
    j=2
    while True:
        try:
            nodelist[line[0]].append((line[j],line[j+1]))
            j+=2
        except:
            break
q=queue.PriorityQueue()
dist[0]=0
for node in nodelist.keys():
    q.put((dist[node],node))

while not q.empty():
    node=q.get()
    if used[node[1]]:
        continue
    else:
        used[node[1]]=True
    for edge in nodelist[node[1]]:
        if dist[edge[0]]>dist[node[1]]+edge[1]:
            dist[edge[0]]=dist[node[1]]+edge[1]
            q.put((dist[edge[0]],edge[0]))

for d in dist.items():
    print(*d)

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <numeric>
#include <climits>
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define repR(i, n) for(int i = (n) - 1; i > -1; i--)
#define rep1(i, n) for(int i = 1; i < (int)(n + 1); i++)
#define rep1R(i, n) for(int i = (n); i > 0; i--)
using namespace std;
static const int INF = INT_MAX;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

static const int N = 2010;
int M[N][N];
int color[N];
int d[N];
int p[N];
int n;

void dijkstra(int s) {
  rep(u, n) {
    color[u] = WHITE;
    d[u] = INF;
  }
  d[s] = 0;
  p[s] = -1;

  while (true) {
    int mincost = INF;
    int u;
    rep(i, n) {
      if (color[i] != BLACK && d[i] < mincost) {
        mincost = d[i];
        u = i;
      }
    }

    if (mincost == INF) break;

    color[u] = BLACK;

    rep(v, n) {
      if (color[v] != BLACK && M[u][v] != INF) {
        if (d[u] + M[u][v] < d[v]) {
          d[v] = d[u] + M[u][v];
          p[v] = u;
          color[v] = GRAY;
        }
      }
    }
  }
}

int main() {
  cin >> n;
  rep(y, n) rep(x, n) {
    int a;
    cin >> a;
    if (a != -1) M[y][x] = a;
    else M[y][x] = INF;
  }
  dijkstra(0);
  rep(v, n) cout << v << " " << d[v] << endl;
  return 0;
}