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++: #include <cstdio>
#include <set>
#include <algorithm>
#include <cstring>

#define INF 1000000
using namespace std;

struct edge
{
  int to, nxt, w;
};

edge E[500005];
int head[10005], cnt = 0, dist[10005];
void add_edge(int u, int v, int w)
{
  E[cnt].to = v;
  E[cnt].w = w;
  E[cnt].nxt = head[u];
  head[u] = cnt++;
}

void dijkstra(int src)
{
  set <pair <int, int> > setds;
  for (int i = 0; i < 10005; i++)
  {
    dist[i] = INF;
  }
  setds.insert(make_pair(0, src));
  dist[src] = 0;
  while (!setds.empty())
  {
    pair<int, int> tmp = *(setds.begin());
    setds.erase(setds.begin());
    int u = tmp.second;
    for (int e = head[u]; ~e; e = E[e].nxt)
    {
      int v = E[e].to;
      int w = E[e].w;
      if (dist[v] > dist[u] + w)
      {
        if (dist[v] != INF)
        {
          setds.erase(setds.find(make_pair(dist[v], v)));
        }
        dist[v] = dist[u] + w;
        setds.insert(make_pair(dist[v], v));
      }
    }
  }
}

int main()
{
  memset(head, -1, sizeof(head));

  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++)
  {
    int v, deg;
    scanf("%d%d", &v, &deg);
    for (int j = 0; j < deg; j++)
    {
      int to, cost;
      scanf("%d%d", &to, &cost);
      add_edge(v, to, cost);
    }
  }
  dijkstra(0);
  for (int i = 0; i < n; i++)
  {
    printf("%d %d\n", i, dist[i]);
  }
}

C++: #include <cstdint>
#include <vector>

using namespace std;

#define GRAPH_SIZE 100
#define WEIGHT_MAX 100001

enum state_t {
  WHITE,
  GRAY,
  BLACK,
};

static uint32_t graph[GRAPH_SIZE][GRAPH_SIZE];
static state_t state[GRAPH_SIZE];
static uint32_t dist[GRAPH_SIZE];

size_t single_source_shotest_path(size_t num)
{
  size_t cost = 0;

  for (uint32_t i = 0; i < num; i++) {
    state[i] = WHITE;
    dist[i] = WEIGHT_MAX;
  }

  state[0] = GRAY;
  dist[0] = 0;

  while (true) {
    size_t minimum_cost = WEIGHT_MAX;
    uint32_t to = 0;
    for (uint32_t i = 0; i < num; i++) {
      if ((dist[i] < minimum_cost) && (state[i] != BLACK)) {
        minimum_cost = dist[i];
        to = i;
      }
    }

    if (minimum_cost == WEIGHT_MAX) break;

    cost += minimum_cost;
    state[to] = BLACK;

    for (uint32_t i = 0; i < num; i++) {
      if (((dist[to] + graph[to][i]) < dist[i]) && state[i] != BLACK) {
        state[i] = GRAY;
        dist[i] = dist[to] + graph[to][i];
      }
    }
  }

  return cost;
}

#include <iostream>

int32_t main()
{
  uint32_t num;
  cin >> num;

  for (uint32_t i = 0; i < num; i++) {
    for (uint32_t j = 0; j < num; j++) {
      graph[i][j] = WEIGHT_MAX;
    }
  }

  for (uint32_t i = 0; i < num; i++) {
    uint32_t index, len;
    cin >> index >> len;
    for (uint32_t j = 0; j < len; j++) {
      uint32_t v, c;
      cin >> v >> c;
      graph[index][v] = c;
    }
  }

  single_source_shotest_path(num);

  for (uint32_t i = 0; i < num; i++) {
    cout << i << " " << dist[i] << endl;
  }

  return 0;
}