Go: package main

import (
	"bufio"
	"fmt"
	"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
}

type Neighbor struct {
	node   int
	weight int
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	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.Printf("%d %d\n", 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) ([][]Neighbor, error) {
	adjacentMatrix := make([][]Neighbor, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			return nil, err
		}
		adjacentMatrix[id] = []Neighbor{}
		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] = append(adjacentMatrix[id], Neighbor{v, c})
		}
	}
	return adjacentMatrix, nil
}

func sssp(nodeStack []int, shortestList []ShortestInfo, adjacentMatrix [][]Neighbor) {
	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 [][]Neighbor) []Edge {
	adjacents := adjacentMatrix[currentNode]
	edges := []Edge{}
	for _, neighbor := range adjacents {
		edges = append(edges, Edge{start: currentNode, end: neighbor.node, weight: neighbor.weight})
	}
	return edges
}

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

C++: #include<bits/stdc++.h>
using namespace std;
 
using Weight=int;
struct Edge {
    int src,dest; Weight weight;
    bool operator<(const Edge &rhs)const{
        return weight<rhs.weight;
    }
};
using Edges=vector<Edge>;
using Graph=vector<Edges>;
 
const Weight INF=1e9;
 
void Dijkstra(const Graph &g,int s,vector<Weight> &d){
    assert(0<=s && s<g.size());
    d.assign(g.size(),INF); d[s]=0;
    vector<int> used(g.size(),0);
    using P=pair<Weight,int>;
    priority_queue<P,vector<P>,greater<P>> que;
    que.push({0,s});
    while(!que.empty()){  
        auto val=que.top(); que.pop();
        Weight dist=val.first;
        int v=val.second;
        if(used[v]) continue;
        used[v]=true;
        for(auto e:g[v]){
            int to=e.dest;
            Weight w=e.weight;
            if(dist+w<d[to]){
                d[to]=dist+w;
                que.push({d[to],to});
            }
        }
    }
}

vector<Weight> Dijkstra(const Graph& g,int s){
    vector<Weight> res;
    Dijkstra(g,s,res);
    return res;
}

vector<Weight> DijkstraPath(const Graph &g,int s,vector<int> &prev){
    prev.assign(g.size(),-1);
    prev[s]=s;
    vector<Weight> d(g.size(),INF);
    assert(0<=s && s<g.size());
    d[s]=0;
    vector<int> used(g.size(),0);
    using P=pair<Weight,int>;
    priority_queue<P,vector<P>,greater<P>> que;
    que.push({0,s});
    while(!que.empty()){  
        auto val=que.top(); que.pop();
        Weight dist=val.first;
        int v=val.second;
        if(used[v]) continue;
        used[v]=true;
        for(auto e:g[v]){
            int to=e.dest;
            Weight w=e.weight;
            if(dist+w<d[to]){
                prev[to]=v;
                d[to]=dist+w;
                que.push({d[to],to});
            }
        }
    }
    return d;
}

vector<int> BuildPath(int s,int t,vector<int> &prev){
    vector<int> res;
    if(prev[s]==-1) return res;
    int v=t;
    while(v!=s){
        res.push_back(v);
        v=prev[v];
    }
    res.push_back(s);
    reverse(res.begin(),res.end());
    return res;
}

int main()
{
    int n;
    cin>>n;
    Graph g(n);
    for(int i=0;i<n;i++)
    {
        int k;
        cin>>k>>k;
        for(int j=0;j<k;j++)
        {
            int v;
            cin>>v;  
            Weight c;
            cin>>c;          
            g[i].push_back((Edge){i,v,c});
        }
    }
    vector<Weight> d;
    vector<int> prev;
    d=DijkstraPath(g,0,prev);
    for(int i=0;i<n;i++)
    {
        cout<<i<<" "<<d[i]<<endl;
        /*
        vector<int> path=BuildPath(0,i,prev);
        for(int i=0;i<path.size();i++) cout<<path[i]<<" ";
        cout<<endl;
        */
    }
    return 0;
}

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

using namespace std;

struct Edge{
    int v, c;

    Edge(int v, int c):v(v), c(c){}

//    bool operator >(Edge &e){
//        return c > e.c;
//    }
};

struct SDto{
    int v, d, from;
    SDto(int v, int d, int from): v(v), d(d), from(from){}

//    bool operator <(SDto &that){
//        return d < that.d;
//    }

    friend bool operator>(SDto s1, SDto s2){
        return s1.d > s2.d;
    }

//    friend bool operator<(SDto s1, SDto s2){
//        return s1.d < s2.d;
//    }
};

// dijkstra
const int MAX_N = 10000, INF = 1 << 28;
int distTo[MAX_N];
int parentOf[MAX_N];
void dijkstra(vector<Edge> G[]);

int main() {
//    SDto s1(1, 1, 1);
//    SDto s2(1, 2, 1);
//    cout << (s1 > s2);

    int n;
    cin >> n;

    // Graph
    vector<Edge> G[n];
    for (int i = 0; i < n; ++i) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; ++j) {
            int v, c;
            cin >> v >> c;
            G[u].emplace_back(v, c);
        }
    }

    dijkstra(G);

    for (int l = 0; l < n; ++l) {
        cout << l << " " << distTo[l] << endl;
    }

    return 0;
}

void dijkstra(vector<Edge> G[]){
    fill(distTo, distTo + sizeof(distTo) / sizeof(*distTo), INF);

    priority_queue<SDto, vector<SDto>, greater<SDto>> pq;

    pq.push(SDto(0, 0, -1));
    while(!pq.empty()) {
        SDto sd = pq.top(); pq.pop();
        if (sd.d < distTo[sd.v]) {
            distTo[sd.v] = sd.d;
            for (auto e: G[sd.v]) {
                if (distTo[e.v] < INF) continue;
                pq.push(SDto(e.v, distTo[sd.v] + e.c, sd.v));
            }
        }
    }
}