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<stdio.h>
#include<stdlib.h>
#include<limits.h>
struct node {
        int id;
        int weight;
        struct node *next;
};
struct node **list;
int *dist, *prev, *heap, *heap_index, heapsize;
void Insert(int, int, int);
void downheap(int);
void upheap(int);
void PQ_Init(int);
void DijkstraPQ(int, int);
main()
{
        int i, j, n, u, k, v, c;
        scanf("%d", &n);
        list = (struct node**)malloc(sizeof(struct node*) * n);
        for (i = 0; i < n; i++) {
                dist = (int*)malloc(sizeof(int) * n);
                prev = (int*)malloc(sizeof(int) * n);
                list[i] = NULL;
        }
        for (i = 0; i < n; i++) {
                scanf("%d%d", &u, &k);
                for (j = 0; j < k; j++) {
                        scanf("%d%d", &v, &c);
                        Insert(u, v, c);
                }
        }
        DijkstraPQ(0, n);
        for (i = 0; i < n; i++) {
                struct node *p, *q;
                printf("%d %d\n", i, dist[i]);
                for (q = list[i], p = q->next; p != NULL; q = p, p = p->next) {
                        q->next = p->next;
                        free(p);
                }
                if (list[i] != NULL) {
                        free(list[i]);
                }
        }
        free(list);
        free(dist);
        free(prev);
        free(heap);
        free(heap_index);
}
void Insert(int a, int b, int weight)
{
        struct node *p = (struct node*)malloc(sizeof(struct node));
        p->id = b;
        p->weight = weight;
        p->next = list[a];
        list[a] = p;
        p = (struct node*)malloc(sizeof(struct node));
    p->id = a;
    p->weight = weight;
        p->next = list[b];
    list[b] = p;
}
void downheap(int k)
{
        int j, v = heap[k];
        while (k < heapsize / 2) {
                j = 2 * k + 1;
                if (j < heapsize - 1 && dist[heap[j]] > dist[heap[j + 1]]) j++;
                if (dist[v] <= dist[heap[j]]) break;
                heap[k] = heap[j];
                heap_index[heap[j]] = k;
                k = j;
        }
        heap[k] = v;
        heap_index[v] = k;
}
void upheap(int j)
{
        int k, v = heap[j];
        while (j > 0) {
                k = (j + 1) / 2 - 1;
                if (dist[v] >= dist[heap[k]]) break;
                heap[j] = heap[k];
                heap_index[heap[k]] = j;
                j = k;
        }
        heap[j] = v;
        heap_index[v] = j;
}
void PQ_Init(int size)
{
        int i;
        heapsize = size;
        heap = (int*)malloc(sizeof(int) * size);
        heap_index = (int*)malloc(sizeof(int) * size);
        for (i = 0; i < size; i++) {
                heap[i] = i;
                heap_index[i] = i;
        }
        for (i = size / 2 - 1; i >= 0; i--) {
                downheap(i);
        }
}
void DijkstraPQ(int p, int size)
{
        int i;
        for (i = 0; i < size; i++) {
                dist[i] = INT_MAX;
                prev[i] = -1;
        }
        dist[p] = 0;
        PQ_Init(size);
        while (heapsize > 0) {
                struct node *n;
                int u = heap[0];
                heap[0] = heap[heapsize - 1];
                heap_index[heap[size - 1]] = 0;
                heapsize--;
                downheap(0);
                for (n = list[u]; n != NULL; n = n->next) {
                        int w = n->weight, newlen = dist[u] + w;
                        if (newlen < dist[n->id]) {
                                dist[n->id] = newlen;
                                prev[n->id] = u;
                                upheap(heap_index[n->id]);
                        }
                }
        }
}

C++: #include <bits/stdc++.h>

using namespace std;

#define Vi vector<int>
#define FOR(i,s,e) for (int i=s; i<e; i++)
#define ITER(v) v.begin(), v.end()

constexpr int N_MAX = 100;

int weight[N_MAX][N_MAX];
int dis[N_MAX];

void set_shortest_distance(const int n) {
    bool ismember[n] = {false};

    int newmember = 0;
    dis[newmember] = 0;
    ismember[newmember] = true;

    FOR(t,0,n-1) {
        FOR(i,0,n) {
            if (weight[newmember][i] < 0) { continue; }
            if (ismember[i]) { continue; }
            const int d = dis[newmember] + weight[newmember][i];
            if (dis[i] < 0 || d < dis[i]) {
                dis[i] = d;
            }
        }
        int min_i = -1, min_d = -1;
        FOR(i,0,n) {
            if (dis[i] < 0) { continue; }
            if (ismember[i]) { continue; }
            if (min_d < 0 || dis[i] < min_d) {
                min_i = i;
                min_d = dis[i];
            }
        }
        newmember = min_i;
        ismember[newmember] = true;
        //cout << "#" << min_i << " " << min_d << endl;
    }
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    FOR(i,0,n) {
        dis[i] = -1;
        FOR(j,0,n) {
            weight[i][j] = -1;
        }
    }

    int u, k, v, c;
    FOR(i,0,n) {
        cin >> u >> k;
        FOR(j,0,k) {
            cin >> v >> c;
            weight[u][v] = c;
        }
    }

    set_shortest_distance(n);

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

    return 0;
}