Go: package main

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

const NIL = -1

type Node struct {
	id     int
	weight int
}

func init() {
	sc.Split(bufio.ScanWords)
}

type NodeHeap []Node

func (h NodeHeap) Len() int           { return len(h) }
func (h NodeHeap) Less(i, j int) bool { return h[i].weight < h[j].weight }
func (h NodeHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *NodeHeap) Push(x interface{}) {
	*h = append(*h, x.(Node))
}

func (h *NodeHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()

	route := make([][]Node, n)
	weight := make([]int, n)
	for i := 0; i < n; i++ {
		weight[i] = NIL
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		route[i] = make([]Node, k)
		for j := 0; j < k; j++ {
			route[u][j] = Node{id: scanInt(), weight: scanInt()}
		}
	}

	start := Node{id: 0, weight: 0}
	h := &NodeHeap{start}
	heap.Init(h)

	for h.Len() > 0 {
		node := heap.Pop(h).(Node)
		if weight[node.id] != NIL {
			continue
		}
		weight[node.id] = node.weight

		for _, nextNode := range route[node.id] {
			if weight[nextNode.id] != NIL {
				continue
			}
			nextNode.weight += node.weight
			heap.Push(h, nextNode)
		}
	}

	for i, w := range weight {
		fmt.Println(i, w)
	}
}

C++: #include <cstdio>
#include <cctype>
#include <climits>
#include <vector>
using namespace std;

#define si static inline
#define gcu getchar_unlocked
si int in() {
	int c, n = 0;
	// bool minus = false; if ((c = gcu()) == '-') minus = true; else ungetc(c, stdin);
	while ((c = gcu()) >= '0' && c <= '9') n = 10 * n + (c - '0');
	return n; }
	// return minus ? -n : n; }
si void scan(char *s) {while (!isspace(*s++ = gcu()));}
#define pcu putchar_unlocked
#define svo si void out
template <typename T>
svo(T n) {
	static char buf[20];
	char *p = buf;
	//if(n < 0) pcu('-'), n *= -1;
	if (!n) *p++ = '0';
	else while (n) *p++ = n % 10 + '0', n /= 10;
	while (p != buf) pcu(*--p); }
svo(const char *s){while(*s)pcu(*s++);}
svo(char *s){while(*s)pcu(*s++);}
svo(char c){pcu(c);}
template <typename T>
//svo(vector<T> &v){for(T &x:v)out(' '),out(x);out('\n');}
svo(vector<T> &v){for(T &x:v)out(&x == &v[0]?"":" "),out(x);out('\n');}
template <typename head, typename... tail>
svo(head&& h, tail&&... t){out(h);out(move(t)...);}
#undef svo
#undef si

template <typename T>
struct heap{
	vector<T> h = {T()};

	void insert(T x) {
		h.push_back(x);
		int c = h.size() - 1;
		for (int p = c / 2; p; c = p, p /= 2)
			if (h[p] < x)
				h[c] = move(h[p]);
			else
				break;
		h[c] = move(x);
	}
	T extract() {
		T res = move(h[1]);
		h[1] = h.back();
		T v = move(h[1]);
		h.pop_back();

		int p = 1, H = h.size();
		for (int c = 2; c < H; p = c, c = p * 2) {
			if (c + 1 < H && h[c] < h[c + 1])
				c++;
			if (h[c] < v)
				break;
			h[p] = move(h[c]);
		}
		h[p] = move(v);

		return move(res);
	}

	bool empty() {
		return h.size() == 1;
	}
};

#define v vector
struct graph {
	struct node {int n, w;};
	v<v<node>> nodes;

	void read(int n) {
		nodes.resize(n);
		for (auto &x: nodes) {
			in();
			for (int k = in(); k--;) {
				int c = in();
				x.push_back({c, in()});
			}
		}
	}

	v<node> dks() {
		v<node> w(nodes.size(), {0, INT_MAX});
		w[0].w = 0;
		heap<node> q;
		q.insert({0, 0});
		while (!q.empty()) {
			node n = q.extract();
			if (w[n.n].n)
				continue;
			w[n.n].n = 1;
			for (node &x: nodes[n.n]) {
				int a = n.w + x.w;
				if (w[x.n].w > a) {
					w[x.n].w = a;
					q.insert({x.n, a});
				}
			}
		}
		return move(w);
	}
};

bool operator < (const graph::node &a, const graph::node &b) {
	return a.w > b.w;
}

int main() {
	graph g;
	g.read(in());
	int i = 0;
	for (auto &x: g.dks())
		out(i++, ' ', x.w, '\n');
}

C++: #include<bits/stdc++.h>
#define to first
#define wgt second 

using namespace std;

typedef pair<int,int> pii;
typedef vector<pii> vec;
typedef vector<vec> Graph;

Graph G(11000);
int n,d[11000];

void SPFA()
{
	bool used[11000];
	queue<int> que;
	memset(used,false,sizeof(used));
	fill(d,d+n,INT_MAX);
	d[0]=0;
	que.push(0);
	while(!que.empty())
	{
		int u=que.front();que.pop();
		for(int i=0;i<G[u].size();i++)
			if(d[G[u][i].to]>d[u]+G[u][i].wgt)
			{
				d[G[u][i].to]=d[u]+G[u][i].wgt;
				que.push(G[u][i].to);
			}
	}
}

int main()
{
	scanf("%d",&n);
	for(int i=0;i<n;i++)
	{
		int u,t;
		scanf("%d%d",&u,&t);
		for(int j=0;j<t;j++)
		{
			int v,w;
			scanf("%d%d",&v,&w);
			G[u].push_back(make_pair(v,w));
		}
	}
	SPFA();
	for(int i=0;i<n;i++)
		printf("%d %d\n",i,d[i]);
	return 0;
}

C++: #define RangeFor(i,n) for(int i=0; i<n; ++i)
#define RvRngFor(i,n) for(int i=n-1; i>=0; --i)

#include <iostream>
#include <vector>
#include <queue>
#include <utility>
#include <numeric>

using std::vector;
using std::cin;
using std::priority_queue;
using std::pair;
using std::make_pair;


vector<int> sssp(vector<vector<pair<int, int> > > c, int start_node = 0){
    int n = c.size();
    priority_queue<pair<int, int>, vector<pair<int,int> >, std::greater<pair<int, int>> > pq;
    vector<int> temp_dist(n, std::numeric_limits<int>::max());
    pq.push(make_pair(0, start_node));

    for(;!pq.empty();pq.pop()){
        auto t = pq.top();
        auto d = t.first;
        auto u = t.second;


        if(d < temp_dist[u]){
            temp_dist[u] = d;
            auto k = c[u].size();
            RangeFor(j, k) {
                pq.push(make_pair(d + c[u][j].second, c[u][j].first));
            }
        }
    }

    return temp_dist;
}

int main(){
    int n; cin >> n;
    vector<vector< pair<int,int> > > c(n);
    RangeFor(i, n) {
        int u;
        cin >> u;
        int k;
        cin >> k;
        c[u] = vector<pair<int, int> >(k);
        RangeFor(j, k) {
            int v;
            cin >> v;
            int d;
            cin >> d;
            c[u][j] = make_pair(v, d);
        }
    }

//    RangeFor(i, n){
//        RangeFor(j, c[i].size()){
//            std::cout << c[i][j].first << ' ' << c[i][j].second;
//        }
//        std::cout << std::endl;
//    }
    
    auto res = sssp(c);
    RangeFor(i, n){
        std::cout << i << ' ' << res[i] << std::endl;
    }
    return 0;
}