Go: package main

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

type Item struct {
	value    int // The value of the item; arbitrary.
	priority int // The priority of the item in the queue.
	// The index is needed by update and is maintained by the heap.Interface methods.
	index int // The index of the item in the heap.
}
type PriorityQueue []*Item

func (pq PriorityQueue) Len() int { return len(pq) }
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 = i
	pq[j].index = j
}
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
}

type Q struct {
	pq *PriorityQueue
	ds map[int]int // It has always same value as pq. For random access.
}

func newQ() *Q {
	pq := new(PriorityQueue)
	heap.Init(pq)
	return &Q{
		pq: pq,
		ds: make(map[int]int),
	}
}
func (q *Q) pop() (u, d int) {
	item := heap.Pop(q.pq).(*Item)
	delete(q.ds, item.value)
	return item.value, item.priority
}
func (q *Q) get(u int) (int, bool) { // returns d
	d, ok := q.ds[u]
	return d, ok
}
func (q *Q) set(u, d int) {
	q.ds[u] = d
	for _, item := range *q.pq {
		if item.value != u {
			continue
		}

		item.priority = d
		heap.Fix(q.pq, item.index)
		return
	}
	heap.Push(q.pq, &Item{
		priority: d,
		value:    u,
	})
}
func (q *Q) len() int {
	return len(q.ds)
}

func main() {
	r := bufio.NewReader(os.Stdin)

	var n int
	fmt.Fscan(r, &n)
	cs := make([]map[int]int, n) // []v_i -> c_i
	for h := 0; h < n; h++ {
		var u, k int
		fmt.Fscan(r, &u, &k)
		m := make(map[int]int)
		for i := 0; i < k; i++ {
			var v, c int
			fmt.Fscan(r, &v, &c)
			m[v] = c
		}

		cs[u] = m
	}

	q := newQ()
	q.set(0, 0)
	visited := make(map[int]struct{})
	out := make([]int, n)

	for q.len() > 0 {
		u, d := q.pop()
		for uu, c := range cs[u] {
			// Consider the connection between u and uu.
			if _, ok := visited[uu]; ok {
				continue
			}
			dd := d + c
			if d, ok := q.get(uu); !ok || d > dd {
				q.set(uu, dd)
			}
		}

		out[u] = d
		visited[u] = struct{}{}
	}

	for u, d := range out {
		fmt.Println(u, d)
	}
}

C++: #include <iostream>
#include <climits>
#include <vector>
using namespace std;
typedef unsigned short ushort;

class blanch{
	public:
		bool visited;
		int distance;
		ushort from;
		ushort to;
};
typedef vector <blanch> vb;
typedef vector <vb> vvb;

int make_graph(vvb &graph, vb &nodes){

	int n=nodes.size();
	for (int i=0; i<n; i++){
		nodes[i].visited = false;
		nodes[i].distance = INT_MAX;
	}

	blanch tmp;
	tmp.visited = false;
	for (int i=0; i<n; i++){
		int n2;
		cin>>tmp.from;
		cin>>n2;

		for (int j=0; j<n2; j++){
			cin>>tmp.to;
			cin>>tmp.distance;
			graph[tmp.from].push_back(tmp);
		}
	}
	return 0;
}

int Shortest_Path(vvb &graph, vb &nodes){

	int p1=0;
	nodes[p1].distance = 0;

	while (p1 != -1){
		nodes[p1].visited=true;
		for (int i = 0; i<(int)graph[p1].size(); i++){
			blanch tmp = graph[p1][i];
			if (!nodes[tmp.to].visited){
				int tmp2 = tmp.distance + nodes[p1].distance;
				if (tmp2 < nodes[tmp.to].distance){
					tmp.distance = tmp2;
					nodes[tmp.to] = tmp;
				}
			}
		}

		p1 = -1;
		int tmp = INT_MAX;
		for (int i=0; i<(int)graph.size(); i++){
			if (!nodes[i].visited && nodes[i].distance<tmp){
				p1 = i;
				tmp = nodes[i].distance;
			}
		}
	}
	return 0;
}

int resultout(vb &nodes){
	for (int i=0; i<(int)nodes.size(); i++){
		cout<<i<<" "<<nodes[i].distance<<endl;
	}
	return 0;
}

int main(void){

	int n;
	cin>>n;
	vvb G(n, vb());
	vb nodes(n);

	make_graph(G, nodes);

	Shortest_Path(G, nodes);

	resultout(nodes);
	G.clear();
	nodes.clear();

	return 0;
}

C++: #include <stdio.h>
#define INF 10000000
typedef struct{
	int node;
	int cost;
} List;

int dist[101];
List list[101][101];
int kazu[101];

int n;

void walk(int x,int step){
	dist[x]=step;
	for(int i=0;i<kazu[x];i++){
		if(dist[list[x][i].node]>step+list[x][i].cost) walk(list[x][i].node,step+list[x][i].cost);
	}
}

int main(void){
	int i,j,w;
	int num;
	scanf("%d",&n);
	for(i=0;i<n;i++){
		scanf("%d",&num);
		scanf("%d",kazu+num);
		for(j=0;j<kazu[num];j++)scanf("%d %d",&(list[num][j].node),&list[num][j].cost);
	}
	for(i=0;i<n;i++) dist[i]=INF;
	walk(0,0);
	
	for(i=0;i<n;i++){
		printf("%d %d\n",i,dist[i]);
	}
	return 0;
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>

#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define repi(i,a,b) for(int i = (a); i < (b); i++)

using namespace std;

typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;

const int INF=1<<29;
const double EPS=1e-9;

const int dx[]={1,0,-1,0},dy[]={0,-1,0,1};
const int MAX_N =1200;
int V;
int cost[MAX_N][MAX_N];
int d[MAX_N];
bool visit[MAX_N];
void dijkstra(int s){
	d[s]=0;
	while(true){
		int v =-1;
		for(int u = 0;u < V;u++){
			if(!visit[u]&&(v==-1||d[u] < d[v])){
				v = u;
			}
		}
		if(v==-1)break;
		visit[v]=true;
		for(int u = 0;u < V;u++){
			d[u] =min(d[u],d[v]+cost[v][u]);
		}
	}
}

int main(){
	cin>>V;
	for(int i =0;i <120;i++){
		d[i]=INF;
		visit[i]=false;
		for(int j =0;j <120;j++){
			cost[i][j]=INF;

		}
	}
	for(int i =0;i < V;i++){
		int u,k;
		cin>>u>>k;
		for(int j =0;j <k;j++){
			int v,c;
			cin>>v>>c;
			cost[u][v]=c;
		}
	}
	dijkstra(0);
	for(int i =0;i <V;i++){
		cout <<i<<" "<<d[i]<<endl;
	}
	return 0;
}

C++: 
#include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
static const int MAX = 10000;
static const int INFTY = 1 << 20;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n;
vector<pair<int, int> > adj[MAX];

void dijkstra() {
	priority_queue<pair<int, int> > PQ;
	int color[MAX];
	int d[MAX];
	for (int i = 0; i < n; i++) {
		d[i] = INFTY;
		color[i] = WHITE;
	}

	d[0] = 0;
	PQ.push(make_pair(0, 0));
	color[0] = GRAY;

	while (!PQ.empty()) {
		pair<int, int>f = PQ.top(); PQ.pop();
		int u = f.second;
		color[u] = BLACK;

		if (d[u] < f.first * (-1))continue;

		for (int j = 0; j < adj[u].size(); j++) {
			int v = adj[u][j].first;
			if (color[v] == BLACK)continue;
			if (d[v] > d[u] + adj[u][j].second) {
				d[v] = d[u] + adj[u][j].second;
				PQ.push(make_pair(d[v] * (-1), v));
				color[v] = GRAY;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		cout << i << " " << (d[i] == INFTY ? -1 : d[i]) << "\n";
	}
}

int main() {
	int k, u, v, c;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		for (int j = 0; j < k; j++) {
			cin >> v >> c;
			adj[u].push_back(make_pair(v, c));
		}
	}
	dijkstra();
	return 0;
}