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<vector>
#include<queue>
#define INF 1000000000

using namespace std;

struct vEdge {
	int adj;
	vector<int> weight;
	vector<int> tovtx;
	vEdge() {}

	void setadj(int a) { adj = a; }

	void setnum(int w, int n2) {
		weight.push_back(w); tovtx.push_back(n2);
	}
};

void dijkstra0(const vector<vEdge>& vedge, vector<int>& cost) {
	int mindex, min, temp, v,w, size = vedge.size(), count = 1;
	vector<bool> optimum(size, false);
	queue<int> qdata;
	cost.at(0) = 0; optimum.at(0) = true;

	while (count < size) {
		mindex = -1; min = INF;
		for (int i = 0; i < size; i++) if (optimum.at(i)) {
			for (int j = 0; j < vedge.at(i).adj;j++){
				v = vedge.at(i).tovtx.at(j);
				if (!optimum.at(v)) {
					w = vedge.at(i).weight.at(j);
					temp = cost.at(i) + w;
					if (temp < min) {
						min = temp;
						mindex = v;
					}
					if (temp < cost.at(v)) cost.at(v) = temp;
				}
			}
		}
		optimum.at(mindex) = true;
		count++;
	}

}

int main(void) {
	int size, num, adj, w, n2;
	cin >> size;

	vector<int> cost(size, INF);
	vector<vEdge> vedge(size);

	for (int i = 0; i < size; i++) {
		cin >> num >> adj;
		vedge.at(num).setadj(adj);
		for (int j = 0; j < adj; j++) {
			cin >> n2 >> w;
			vedge.at(num).setnum(w, n2);
		}
	}
	dijkstra0(vedge, cost);

	for (int i = 0; i < size; i++) cout << i << " " << cost.at(i) << endl;
	return 0;

}

C++: #include<bits/stdc++.h>
#define INF 0x3f3f3f3f 
using namespace std;
const int maxn = 11111;
int n, m;
struct edge
{
	int v, cost;
	edge(int _v=0,int _cost=0):v(_v),cost(_cost){}
};
vector<edge> g[maxn];
bool book[maxn];
int dis[maxn];
void myinit()
{
	memset(book, 0, sizeof(book));
	for (int i = 0; i < maxn; i++)
	{
		g[i].clear();
	}
	fill(dis, dis + maxn,INF);
}
void SPFA(int s)
{
	queue<int> q;
	q.push(s);
	book[s] = 1;//加入队列并标记 
	while (!q.empty())
	{
		int temp = q.front();
		q.pop();
		book[temp] = 0;//弹出队列并取消标记 
		for (int i = 0; i < g[temp].size(); i++)
		{
			if (g[temp][i].cost + dis[temp] < dis[g[temp][i].v])//比较 
			{
				dis[g[temp][i].v] = g[temp][i].cost + dis[temp];//更新路径 
				if (!book[g[temp][i].v])//若该点不在队列 
				{
					q.push(g[temp][i].v);
					book[g[temp][i].v] = 1;
				}
			}
		}
	}
}
void addedge(int u, int v, int w)
{
	g[u].push_back(edge(v, w));
}
int main()

{
	cin >> n;
	m = 0;
	myinit();
	for (int i = 0;i < n;i++)
	{
		int ve, en, co;
		int k;
		cin >> ve >> k;
		for (int j = 0;j < k;j++)
		{
			cin >> en >> co;
			addedge(ve, en, co);
		}
	}
	dis[0] = 0;
	SPFA(0);
	for (int i = 0;i < n;i++)
		cout << i << " " << dis[i] << endl;
	return 0;
}

C++: #include <iostream>
#include <algorithm> 
#include <cstdio>
#include <cstring>
using namespace std;

#define INF 1000000 //极大的数 
const int N = 1009;

int d[N],v[N],w[N][N]; //d[i]为起始点到i的最短路径   v[i]为标记数组    w[x][y]表示边(x,y)的长度. 
int main(){
	int n,m,a,b,c,beg,end;
	while((scanf("%d",&n))!=EOF){
		memset(w,0,sizeof(w));
		memset(d,0,sizeof(d));
		memset(v,0,sizeof(v));
		for(int i=0;i<n;i++){
			scanf("%d%d",&a,&m);
			for(int j=0;j<m;j++){
				scanf("%d%d",&b,&c);
				w[i][b] = w[b][i] = c;
			}
		}
		for(int i=0;i<n;i++) d[i] = (i==0?0:INF);
		for(int i=0;i<n;i++){
			int x,a = INF; 
			for(int y=0;y<n;y++)
				if(!v[y]&&d[y]<=a) a = d[x=y];
				v[x] = 1;
		for(int j=0; j<n; j++)
                if(!v[j] && w[x][j] && d[x]+w[x][j] < d[j])
                    d[j] = d[x]+w[x][j];
		}
		for(int i=0;i<n;i++){
			printf("%d %d\n",i,d[i]);
		}
	}	
}

C++: #include <iostream>
using namespace std;
static const int MAX = 100;
static const int INFTY = (1<<21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n, M[MAX][MAX];

void dijkstra()
{
    int minv;
    int d[MAX], color[MAX];

    for(int i=0; i<n; i++)
    {
        d[i] = INFTY;
        color[i] = WHITE;
    }

    d[0] = 0;
    color[0] = GRAY;
    while(1)
    {
        minv = INFTY;
        int u = -1;
        for(int i=0; i<n; i++)
        {
            if(minv > d[i] && color[i] != BLACK)
            {
                u = i;
                minv = d[i];
            }
        }
        if(u == -1) break;
        color[u] = BLACK;
        for(int v=0; v<n; v++)
        {
            if(color[v]!=BLACK && M[u][v]!=INFTY)
            {
                if(d[v]>d[u]+M[u][v])
                {
                    d[v] = d[u] + M[u][v];
                    color[v] = GRAY;
                }
            }
        }
    }
    for(int i=0; i<n; i++)
    {
        cout << i << " " << (d[i]==INFTY ? -1:d[i]) << endl;
    }
}

int main()
{
    cin >> n;
    for(int i=0; i<n; i++)
    {
        for(int j=0; j<n; j++) M[i][j] = INFTY;
    }

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

C++: #include<iostream>
int main(){
  int u,k,C,V,A[1000][1000],D[1000][1000],n;
  std::cin >> n;
  for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j] = 200001;
  for(int i=0;i<n;i++){     std::cin >> u >> k;
    for(int j=0;j<k;j++){   std::cin >> V >> C;
      D[u][V] = C;}}
  for(int i=0;i<n;i++)D[i][i] = 0;
  for(int k=0;k<n;k++)for(int i=0;i<n;i++)for(int j=0;j<n;j++)D[i][j]= std::min(D[i][j],D[i][k] + D[k][j]);
  for(int i=0;i<n;i++)std::cout << i << " " << D[0][i] << std::endl;
  return 0;
}