Go: package main

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

const (
	MAX_N      = 10000
	MAX_WEIGHT = 100000
)

type Edge struct {
	start  int
	end    int
	weight int
}

type ShortestInfo struct {
	edges    []Edge
	shortest int
}

func main() {
	doMain(os.Stdin)
}

func doMain(reader io.Reader) {
	sc := bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	shortestList := make([]ShortestInfo, n)
	for i := 1; i < n; i++ {
		shortestList[i] = ShortestInfo{edges: []Edge{}, shortest: MAX_N*MAX_WEIGHT + 1}
	}

	adjacentMatrix, err := createAdjacentMatrix(n, sc)
	if err != nil {
		panic(err)
	}

	sssp([]int{0}, shortestList, adjacentMatrix)
	for _, v := range shortestList {
		fmt.Println(v.getEnd(), v.shortest)
	}
}

func (si ShortestInfo) getEnd() int {
	if len(si.edges) == 0 {
		return 0
	} else {
		return si.edges[len(si.edges)-1].end
	}
}

func createAdjacentMatrix(n int, sc *bufio.Scanner) ([][]int, error) {
	adjacentMatrix := make([][]int, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			return nil, err
		}
		adjacentMatrix[id] = make([]int, n)
		for j := 0; j < n; j++ {
			adjacentMatrix[id][j] = -1
		}
		vertexNum, err := nextInt(sc)
		if err != nil {
			return nil, err
		}
		for j := 0; j < vertexNum; j++ {
			v, err := nextInt(sc)
			if err != nil {
				return nil, err
			}
			c, err := nextInt(sc)
			if err != nil {
				return nil, err
			}
			adjacentMatrix[id][v] = c
		}
	}
	return adjacentMatrix, nil
}

func sssp(nodeStack []int, shortestList []ShortestInfo, adjacentMatrix [][]int) {
	for len(nodeStack) > 0 {
		currentNode := nodeStack[0]
		nodeStack = nodeStack[1:]
		currentShortest := getShortest(currentNode, shortestList)
		adjacents := findAdjacents(currentNode, adjacentMatrix)
		for i := 0; i < len(adjacents); i++ {
			adj := adjacents[i]
			if currentShortest.shortest+adj.weight < getShortest(adj.end, shortestList).shortest {
				setShortest(adj.end, adj, currentShortest, shortestList)
				nodeStack = append(nodeStack, adj.end)
			}
		}
	}
}

func getShortest(node int, shortestList []ShortestInfo) ShortestInfo {
	return shortestList[node]
}

func setShortest(node int, edge Edge, currentShortest ShortestInfo, shortestList []ShortestInfo) {
	newEdges := make([]Edge, len(currentShortest.edges)+1)
	for i := 0; i < len(newEdges)-1; i++ {
		newEdges[i] = currentShortest.edges[i]
	}
	newEdges[len(newEdges)-1] = edge
	shortestInfo := ShortestInfo{edges: newEdges, shortest: currentShortest.shortest + edge.weight}
	shortestList[node] = shortestInfo
}

func findAdjacents(currentNode int, adjacentMatrix [][]int) []Edge {
	adjacents := adjacentMatrix[currentNode]
	edges := []Edge{}
	for i, v := range adjacents {
		if v >= 0 {
			edges = append(edges, Edge{start: currentNode, end: i, weight: v})
		}
	}
	return edges
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

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

//def
#define debug(x) cout << #x << ": " << x << '\n'
#define out(x) cout << x << '\n'
#define repeat(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define revrepeat(i, a, b) for (int i = (int)(b)-1; i >= (int)(a); i--)
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define revrep(i, n) for (int i = (int)(n)-1; i >= 0; i--)
#define foreach(e, v) for (auto &e : v)
#define all(x) (x).begin(), (x).end()
#define CYES cout << "Yes" << endl
#define CNO cout << "No" << endl
#define SPC(x) cout << fixed << setprecision(x)
#define ZERO(a) memset(a, 0, sizeof(a))
#define MINUS(a) memset(a, 0xff, sizeof(a))

typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<vector<int>> vii;
typedef vector<ll> vl;
typedef vector<vector<ll>> vll;
typedef pair<int, int> P;
constexpr int MOD = 1e9 + 7;
constexpr int INF = __INT_MAX__;               // 2^31 - 1
constexpr long long INFLL = __LONG_LONG_MAX__; // 2^61 - 1
constexpr int MAX_N = 1e5 + 5;
constexpr double PI = acos(-1);

int pre[MAX_N];
long long d[MAX_N];
bool seen[MAX_N];
struct Edge {
    int to;
    long long cost;
};
// require: cost value is positive
// O(nlog|v|)
void dijkstra(int s, vector<vector<Edge>> &graph) {
    fill(pre, pre + MAX_N, -1);
    fill(seen, seen + MAX_N, false);
    fill(d, d + MAX_N, INF);

    auto comPair = [](const P one, const P two) {
        return one.second > two.second;
    };
    // que(v, distance)
    priority_queue<P, vector<P>, decltype(comPair)> que(comPair);
    que.emplace(0, 0);
    d[0] = 0;
    seen[0] = true;

    while (!que.empty()) {
        int u = que.top().first;
        que.pop();

        for (auto e : graph[u]) {
            int v = e.to;
            int c = e.cost;

            if (not seen[v] and d[v] > d[u] + c) {
                d[v] = d[u] + c;
                pre[v] = u;
                que.emplace(v, d[v]);
            }
        }
        seen[u] = true;
    }
};

int main() {
    int n;
    cin >> n;
    vector<vector<Edge>> graph(n);
    int k;
    rep(i, n) {
        cin >> k;
        cin >> k;
        rep(j, k) {
            Edge e;
            cin >> e.to >> e.cost;
            graph[i].push_back(e);
        }
    }
    dijkstra(0, graph);
    rep(i, n) {
        cout << i << ' ' << d[i] << endl;
    }
}

C++: 
#include<iostream>
#include<cstdio>
#include<set>
#include<queue>
#include<cstring>
#include<algorithm>
typedef long long ll;
#define inf 1000000000
using namespace std;


struct _node
{
	ll v,w;
	//:v(a),w(b)
	_node(ll a=0,ll b=0)
	{
		v=a;
		w=b;
	
	};
	bool operator <(const _node & other) const
	{
		return other.w<w;
	}
	
}node;

vector<_node> A[10500];
bool mark[10500];
ll dis[10500];

priority_queue<_node> Q;

void add(ll a,ll b,ll c)
{
	//cout<<a<<" "<<b<<" "<<c<<endl; 
	A[a].push_back(_node(b,c));
	//cout<<A[a][0].w<<endl;
	
}


void dlsj(ll n)
{
	//while(!Q.empty())Q.pop();
	ll v,v1;
	_node tmp;
	for(int i=0;i<n;i++)dis[i]=inf;

	dis[0]=0;
	Q.push(_node(0,0));
	
	while(!Q.empty())
	{
		tmp=Q.top();
		Q.pop();
		v=tmp.v;
		//cout<<v<<endl;
		//cout<<A[v].size()<<endl;
		if(mark[v])continue;
		mark[v]=1;
		for(int i=0;i<A[v].size();i++)
		{
			
			if(mark[A[v][i].v])continue;
			v1=A[v][i].v;
			//cout<<i<<" "; 
			//cout<<dis[2]<<" "<<dis[A[v][i].v]<<" "<<dis[v]+A[v][i].w<<endl;
			//cout<<A[v][i].v<<endl;
			if(dis[v1]>dis[v]+A[v][i].w)
			{
				
				dis[v1]=dis[v]+A[v][i].w;
				
				Q.push(_node(A[v][i].v,dis[v1]));
				
			}
			
			
			
			
		} 
		
		
	}
	
	
	
	
}




int main()
{
	ll n;
	scanf("%lld",&n);
	add(0,0,0);
	for(int i=1;i<=n;i++)
	{
		ll u,k,a,b;
		scanf("%lld%lld",&u,&k);
		while(k--)
		{
			scanf("%lld%lld",&a,&b);
			add(u,a,b);
		}
		
		
		
		
	} 
	dlsj(n);
	for(int i=0;i<n;i++)
	{
		//cout<<"e"<<endl;
		cout<<i<<" "<<dis[i]<<endl;
		
	}
	
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <utility>
#include <queue>

using namespace std;
 
vector<int> dijkstra(int s, vector<vector<pair<int, int> > >& G) {
	const int INF = 1e9;
	const int N = G.size();
	vector<int> cost(N, INF);
	priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > pq;
	cost[s] = 0;
	pq.push(make_pair(0, s));
	while (!pq.empty()) {
		pair<int, int> p = pq.top(); pq.pop();
		int now = p.second;
		if (cost[now] < p.first) continue;
		for (auto next : G[now]) {
			int nv = next.first, nw = next.second;
			if (cost[nv] > cost[now] + nw) {
				cost[nv] = cost[now] + nw;
				pq.push(make_pair(cost[nv], nv));
			}
		}
	}
	return cost;
}

int main() {
	int n; cin >> n;
	vector<vector<pair<int, int> > > G(n);
	for (int i = 0; i < n; ++i) {
		int u, k; cin >> u >> k;
		while (k--) {
			int v, c; cin >> v >> c;
			G[u].push_back(make_pair(v, c));
		}
	}
	vector<int> ans(dijkstra(0, G));
	for (int i = 0; i < n; ++i)
		cout << i << " " << ans[i] << endl;

	return 0;
}