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()

	list := make([][]int, n)
	weight := make([]int, n)
	for i := range list {
		list[i] = make([]int, n)
		weight[i] = NIL
		for j := range list[i] {
			list[i][j] = NIL
		}
	}

	for i := 0; i < n; i++ {
		u := scanInt()
		k := scanInt()
		for j := 0; j < k; j++ {
			v := scanInt()
			w := scanInt()
			list[u][v] = w
		}
	}

	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 i, w := range list[node.id] {
			if w == NIL {
				continue
			}
			heap.Push(h, Node{id: i, weight: w + node.weight})
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 0; i < n; i++ {
		fmt.Fprint(w, i)
		fmt.Fprint(w, " ")
		fmt.Fprint(w, weight[i])
		fmt.Fprintln(w)
	}
	w.Flush()
}

C++: #include <cstdio>
static const int INFTY = (1 << 21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n, **M;
int *d;

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

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

    while (1) {
        u = -1;
        minv = INFTY;
        for (int i = 0; i < n; i++) {
            if (color[i] != BLACK && d[i] < minv) {
                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[u] + M[u][v] < d[v]) {
                    d[v] = d[u] + M[u][v];
                    color[v] = GRAY;
                }             
            }
        }
    }
    
    for (int i = 0; i < n; i++) {
        printf("%d %d", i, d[i]);
        if (i != n - 1) { printf("\n"); }
    }
}

int main() {
    scanf("%d", &n);

    M = new int*[n];
    for (int i = 0; i < n; i++) {
        M[i] = new int[n];
        for (int j = 0; j < n; j++) {
            M[i][j] = INFTY;
        }
    }

    for (int i = 0; i < n; i++) {
        int u, k;
        scanf("%d %d", &u, &k);
        for (int j = 0; j < k; j++) {
            int v, c;
            scanf("%d %d", &v, &c);
            M[u][v] = c;
        }
    }

    dijkstra();

    return 0;
}

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 < MAX; 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 <bits/stdc++.h> 
using namespace std; 
typedef long long ll; 
#define FOR(I,A,B) for(ll I = (A); I < (B); ++I) 
const ll INF=1e9+7; 
const ll N = 101; 


class dijkstra{ 
//0indexed 
public: 
	int v,startv; 
	vector<int> d; 
	vector<vector<pair<int,int> > >e; 

void initsize(int n0){ 
	d.resize(n0); 
	for(int i=0;i<n0;i++)d[i]=INT_MAX; 
	vector<pair<int,int> > ep; 
	for(int i=0;i<n0;i++)e.push_back(ep); 
	v=n0; 
} 

void initstart(int s){ 
	startv=s;
	d[s]=0;
}

void make_edge(int x,int y,int cost){ 
	e[x].push_back(make_pair(y,cost)); 
	e[y].push_back(make_pair(x,cost)); 
}

void make_edgedir(int x,int y,int cost){ 
	e[x].push_back(make_pair(y,cost)); 
}

void calcdistance(){ 
	// <-cost,x> 
	//cost startv->x 
	priority_queue<pair<int,int> > q; 
	pair<int,int> p; 
	vector<bool> did; 
	for(int i=0;i<v;i++)did.push_back(false); 
	did[startv]=true; 
	for(int i=0;i<e[startv].size();i++){ 
		p.first=-e[startv][i].second; 
		p.second=e[startv][i].first; 
		q.push(p); 
	}

	while(q.size()!=0){ 
		pair<int,int> p; 
		p=q.top(); 
		q.pop(); 
		int x,costsx; 
		x=p.second; 
		costsx=-p.first; 
		if(did[x]==true)continue; 
		did[x]=true; 
		d[x]=costsx; 

		for(int i=0;i<e[x].size();i++){ 
			p.first=-(d[x]+e[x][i].second); 
			p.second=e[x][i].first; 
			if(did[p.second]==false)q.push(p); 
		} 
	} 
} 

}; 



int main(){ 
	dijkstra di;
	int n;
	cin>>n;
	di.initsize(n);
	di.initstart(0);
	FOR(i,0,n){
		int u,k;
		cin>>u>>k;
		FOR(j,0,k){
			int x,co;
			cin>>x>>co;
			di.make_edgedir(u,x,co);
		}
	}
	di.calcdistance();
	FOR(i,0,n){
		cout<<i<<" "<<di.d[i]<<endl;
	}
	return 0; 
}

C++: #include <stdio.h>
#define INF (1<<21)

int main(void)
{
 int i,j,n,m,u,k,l,v,c,a[10000],b[10000],d[10000][10000];

 scanf("%d",&n);
 
 for(i=0;i<n;i++){
 	scanf("%d %d",&u,&k);
 	a[i]=INF;
 	b[i]=0;
 	for(j=0;j<k;j++){
 		scanf("%d %d",&v,&c);
 		d[u][v]=c;
 	}
 }
 a[0]=0;
 
 while(1){
 	
 	l=-1;
 	m=INF;
 	
 	for(i=0;i<n;i++){
 		if(a[i]<m && b[i]==0){
 			m=a[i];
 			l=i;
 		}
 	}
 	
 	if(l==-1) break;
 	
 	b[l]=1;
 	
 	for(i=0;i<n;i++){
 		if(a[i]>=d[l][i]+a[l]) a[i]=d[l][i]+a[l];
 	}
 }
 
 for(i=0;i<n;i++){
 	if(a[i]==INF) printf("%d -1\n",i);
 	else printf("%d %d\n",i,a[i]);
 }
 
 return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

#define INF 1<<29
#define MAXV 100

int V;      //????????°
int cost[MAXV+10][MAXV+10];

vector<int> dijkstra(int s){
    vector<int> d(V,INF);
    bool used[MAXV+10];
    for(int i=0;i<MAXV+10;i++) used[i]=false;

    d[s]=0;
    while(true){
        //??????????????????????????????????????§s??????????????¢???????°?????????????v??¨??????
        int v=-1;
        for(int u=0;u<V;u++){
            if(!used[u] and (v==-1 or d[u]<d[v])) v=u;
        }

        if(v==-1) break;
        
        used[v]=true;
        for(int u=0;u<V;u++){
            d[u] = min(d[u],d[v]+cost[v][u]);
        }
    }
    return d;
}

int main(){
    // initialize
    for(int i=0;i<MAXV+10;i++) for(int j=0;j<MAXV+10;j++) cost[i][j]=INF;

    cin >> V;
    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[i][v]=c;
//            cost[v][i]=c;
        }
    }

    vector<int> dis = dijkstra(0);
    for(int i=0;i<dis.size();i++){
        printf("%d %d\n",i,dis[i]);
    }
}