Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

var infty = 1000000000

type DirectedGraphNodeID int

type DirectedGraphNode struct {
	key         DirectedGraphNodeID
	adjacents   []*DirectedGraphNode
	costs       []int
	distance    int
	predecessor *DirectedGraphNode
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]*DirectedGraphNode, nNodes)
	for i := 0; i < nNodes; i++ {
		node := DirectedGraphNode{}
		node.key = DirectedGraphNodeID(i)
		node.distance = infty
		graph.nodes[i] = &node
	}
	return &graph
}

type DirectedGraph struct {
	nodes []*DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(i, j DirectedGraphNodeID, cost int) {
	g.nodes[i].adjacents = append(g.nodes[i].adjacents, g.nodes[j])
	g.nodes[i].costs = append(g.nodes[i].costs, cost)
}

func (g *DirectedGraph) print() {
	for i := 0; i < len(g.nodes); i++ {
		node := g.nodes[i]
		key := node.key
		strings := []string{strconv.Itoa(int(key)), strconv.Itoa(node.distance)}
		for j := 0; j < len(node.adjacents); j++ {
			nodeJ := fmt.Sprintf("(%v, %v)", node.adjacents[j].key, node.costs[j])
			strings = append(strings, nodeJ)
		}
		fmt.Printf("%v\n", strings)
	}
}

func (g *DirectedGraph) relaxEdge(l, r *DirectedGraphNode, w int) {
	if r.distance > l.distance+w {
		// fmt.Printf("%v -> %v, %v\n", l.key, r.key, l.distance+w)
		r.distance = l.distance + w
		r.predecessor = l
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	graph := newDirectedGraph(nNodes)

	for i := 0; i < nNodes; i++ {
		iNode := DirectedGraphNodeID(nextInt())
		nAdjacent := nextInt()
		for j := 0; j < nAdjacent; j++ {
			jNode := DirectedGraphNodeID(nextInt())
			cost := nextInt()
			graph.setAdjacency(iNode, jNode, cost)
		}
	}

	graph.nodes[0].distance = 0
	for iNode := 0; iNode < nNodes; iNode++ {
		for iLeft := 0; iLeft < len(graph.nodes); iLeft++ {
			nodeLeft := graph.nodes[iLeft]
			for iRight := 0; iRight < len(nodeLeft.adjacents); iRight++ {
				nodeRight := nodeLeft.adjacents[iRight]
				cost := nodeLeft.costs[iRight]
				graph.relaxEdge(nodeLeft, nodeRight, cost)
			}
		}
	}

	// graph.print()

	for iNode := 0; iNode < len(graph.nodes); iNode++ {
		node := graph.nodes[iNode]
		fmt.Println(node.key, node.distance)
	}
}

C++: #include <iostream>
#include <cstring>
#define MAX 120000
using namespace std;

int matrix[105][105],n,closest[105],close[105];

void djst(){
    int i,j,k;
    for(i=1;i<n;i++){
        if(matrix[0][i]!=-1)close[i]=matrix[0][i];
    }
    while(1){
        int mi=MAX,rec=-1;
        for(i=1;i<n;i++){
            if(close[i]!=-1&&close[i]<mi&&closest[i]==-1){
                mi=close[i];
                rec=i;
            }
        }
        if(rec==-1)break;
        closest[rec]=mi;
        close[rec]=MAX;
        for(j=1;j<n;j++){
            if(closest[j]==-1&&matrix[rec][j]!=-1){
                if(mi+matrix[rec][j]<close[j]||close[j]==-1)close[j]=mi+matrix[rec][j];
            }
        }
    }
}
int main(){
    memset(close,-1,sizeof(close));//memset??????????????¨0???-1???????????°???????§????
    memset(closest,-1,sizeof(closest));
    memset(matrix,-1,sizeof(matrix));
    int i,j;
    cin>>n;
    for(i=0;i<n;i++){
        int a,b;
        cin>>a>>b;
        for(j=0;j<b;j++){
            int c,d;
            cin>>c>>d;
            matrix[a][c]=d;
        }
    }
    closest[0]=0;
    djst();
    for(i=0;i<n;i++){
        cout<<i<<" "<<closest[i]<<endl;
    }
    return 0;
}

C++: #include <iostream>
#include <algorithm>
#define N 100
#define INF (1<<30)
using namespace std;

int n, M[N][N], d[N], color[N] = {0};

void Dijk(int s) {
	int min;
	for (int i = 0;i < n;i++) d[i] = INF;
	d[s] = 0;
	while (true) {
		int u=-1;
	    min = INF;
		for (int i = 0;i < n;i++) {
			if (color[i] == 0 && d[i] < min)
				min = d[i];
			    u = i;
		}

		if (u==-1) break;

		color[u] = 1;

		for (int v = 0;v < n;v++) {
			if (color[v] == 0 && M[u][v] != INF)
				if (d[v] > d[u] + M[u][v]) {
					d[v] = d[u] + M[u][v];
				}
		}
	}

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

}

int main() {

	for (int i = 0;i < N;i++)
		for (int j = 0;j < N;j++) M[i][j] = INF;

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

	Dijk(0);

}

C++: #include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
const ll inf=99999999999999999;
#define rep(i,t,n) for(int i=t;i<n;i++)
const int maxn=1e2+7;
ll d[maxn][maxn];
int main(){
    int a,n,m,x;ll z;
    scanf("%d",&n);
    rep(i,0,n) rep(j,0,n) d[i][j]=inf;
    rep(i,0,n) d[i][i]=0;
    rep(i,0,n){
        scanf("%d%d",&a,&m);
        rep(j,0,m){
            scanf("%d%lld",&x,&z);
            d[a][x]=min(d[a][x],z);
        }
    }
    if(n==1){
        printf("0 0\n");
        return 0;
    }
    rep(k,0,n) rep(i,0,n) rep(j,0,n) d[i][j]=min(d[i][j],d[i][k]+d[k][j]);
    rep(i,0,n) printf("%d %lld\n",i,d[0][i]);
    return 0;
}

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

typedef long long ll;

struct Edge {
    ll t,w;
};

struct State {
    ll v;
    ll score;
    bool operator < (const State& tgt) const {
	return score > tgt.score;
    }
};

vector<ll> dijkstra(vector<vector<Edge>>& G, const int start) {
    const ll V = G.size();

    vector<ll>res(V,INT_MAX);
    priority_queue<State> q;
    q.push( State{0,0} );
    while( q.size() ) {
	State s = q.top(); q.pop();
	if( res[s.v] != INT_MAX ) continue;
	res[s.v] = s.score;
	for(auto& e : G[s.v]) {
	    if( res[e.t] != INT_MAX ) continue;
	    q.push( State{e.t, s.score + e.w} );
	}
    }
    return res;
}


int main () {

    ll V; cin >> V;
    vector<vector<Edge>> G(V);
    for(int i=0; i<V; i++) {
	ll u,k; cin >> u >> k;
	for(int j=0; j<k; j++) {
	    ll v,w; cin >> v >> w;
	    G[i].push_back( Edge{v,w} );
	}
    }
    vector<ll> res = dijkstra(G,0);
    for(int i=0; i<V; i++) {
	cout << i << " " << res[i] << endl;
    }    
    return 0;
}

C++: #include<iostream>
using namespace std;
static const int MAX = 100;
static const int INFTY = 1000001;
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

//Mは隣接行列
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];
            }
        }
        //cout << "u=" << u << endl;
        if(u == -1) break;
        color[u] = BLACK;
        //d[i]にBLACkからiへの最短経路を入れる
        for(int i=0;  i<n; i++){
            if(color[i]!=BLACK) d[i] = min(M[u][i]+d[u], d[i]);
        }
    }
    for(int i=0; i<n; i++){
        cout << i << " " << 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;
}