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<bits/stdc++.h>
using namespace std;
const int MAXN = 100+7;
const int INF = 1e6+7;
int m[MAXN][MAXN];
int d[MAXN];
bool visit[MAXN];
int n;
set<int> s;
void djas()
{
    d[0] = 0;
    for(int i = 1; i < n; i++)
    {
        d[i] = INF;
    }
    while(s.size() != n)
    {
        int min_d = INF;
        int s1;
        for(int j = 0; j < n; j++)
        {
            if(d[j]<min_d && visit[j]==false)
            {
                min_d = d[j];
                s1 = j;
            }
        }

        s.insert(s1);
        visit[s1] = true;
        for(int j = 1; j < n; j++)
        {
            if(m[s1][j]!=-1 && d[s1]+m[s1][j]<d[j] && j!=s1 && visit[j]==false){
                d[j] = d[s1]+m[s1][j];
            }
        }
    }
}
int main()
{
//    freopen("in.txt", "r", stdin);
    memset(visit, false, sizeof(visit));
    memset(m, -1, sizeof(m));
    scanf("%d", &n);
    for(int i = 0; i < n; i++)
    {
        int id;
        scanf("%d", &id);
        int degree;
        scanf("%d", &degree);
        for(int j = 0; j < degree; j++)
        {
            int v;
            scanf("%d", &v);
            int c;
            scanf("%d", &c);
            m[id][v] = c;
        }
    }
    djas();
    for(int i = 0; i < n; i++)
    {
        printf("%d %d\n", i, d[i]);
    }

    return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

#define Vi vector<int>
#define FOR(i,s,e) for (int i=s; i<e; i++)
#define ITER(v) v.begin(), v.end()

constexpr int N_MAX = 100;

int weight[N_MAX][N_MAX];
int dis[N_MAX];

void exhaust_search(const int cur, const int d, const int n, std::array<bool, N_MAX> isvisited) {
    isvisited[cur] = true;
    if (dis[cur] < 0 || d < dis[cur]) { dis[cur] = d; }
    for (int next = 0; next < n; ++next) {
        if (isvisited[next]) { continue; }
        if (weight[cur][next] < 0) { continue; }
        exhaust_search(next, d + weight[cur][next], n, isvisited);
    }
}

void set_shortest_distance(const int n) {
    std::array<bool, N_MAX> isvisited;
    isvisited.fill(false);
    exhaust_search(0, 0, n, isvisited);
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;

    FOR(i,0,n) {
        dis[i] = -1;
        FOR(j,0,n) {
            weight[i][j] = -1;
        }
    }

    int u, k, v, c;
    FOR(i,0,n) {
        cin >> u >> k;
        FOR(j,0,k) {
            cin >> v >> c;
            weight[u][v] = c;
        }
    }

    set_shortest_distance(n);

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

    return 0;
}

C++: #include<iostream>
#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
int main() {
	int n, u, k, v, c, i, j, d[100][100], m[100][100], o, p[100] = { 0 }, e, q = 0;
	memset(m, 0x7f, sizeof(m));
	memset(d, 0x7f, sizeof(d));
	d[0][0] = 0;
	cin >> n;
	for (i = 0; i < n; i++) {
		cin >> u >> k;
		for (j = 0; j < k; j++) {
			cin >> v >> c;
			m[u][v] = c;
		}
	}
	p[0] = 1;
	for (i = 1; i < n; i++) {
		o = d[0][n - 1];
		for (j = 0; j < n; j++) {
			d[i][j] = min(d[i][j], m[q][j] + d[i - 1][q]);
			d[i][j] = min(d[i][j], d[i - 1][j]);
			if (o >= d[i][j] && p[j] == 0) {
				e = j;
				o = d[i][j];
			}
		}
		p[e] = 1;
		q = e;
	}
	for (i = 0; i < n; i++)cout << i << ' ' << d[n - 1][i] << endl;
	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#define MAX 101
#define INF 100001
using namespace std;

int n, isSelected[MAX], dist[MAX];
vector<pair<int, int>> ver[MAX];

void initDijkstra(void);
void dijkstra(void);
bool doesFinished(void);

int main() {
	int i, j, id, k, v, c;
	cin >> n;
	for (i = 0; i < n; i++) {
		cin >> id >> k;
		for (j = 0; j < k; j++) {
			cin >> v >> c;
			ver[id].push_back(make_pair(v, c));
		}
	}

	initDijkstra();

	while (!doesFinished())dijkstra();

	for (i = 0; i < n; i++) {
		cout << i << " " << dist[i] << endl;
	}

	return 0;
}

void initDijkstra(void) {
	dist[0] = 0;
	isSelected[0] = 1;
	for (int i = 1; i <= n; i++)dist[i] = INF;
}

void dijkstra(void) {
	int i, minu, minp, mindist = INF;
	vector<pair<int, int>>::iterator itv;
	for (i = 0; i < n; i++) {
		if (isSelected[i] == 0)continue;
		for (itv = ver[i].begin(); itv != ver[i].end(); itv++){
			if (isSelected[itv->first] == 1)continue;
			if (itv->second < mindist) {
				mindist = itv->second;
				minu = itv->first;
				minp = i;
			}
		}
	}
	isSelected[minu] = 1;
	dist[minu] = dist[minp] + mindist;
}

bool doesFinished(void) {
	for (int i = 0; i < n; i++) {
		if (isSelected[i] == 0)return false;
	}
	return true;
}