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<cstdio>

const static int MAX = 100;
const static int WHITE = 0;
const static int GRAY = 1;
const static int BLACK = 2;
const static int INFTY = (1<<30);

int M[MAX][MAX];
int color[MAX];
int d[MAX];
int p[MAX];
int n;

void dijkstra()
{
	//初始化
	for(int i=0; i<n; i++)
	{
		color[i] = WHITE;
		d[i] = INFTY;
	}
	int u;
	int mincost;
	d[0] = 0;
	p[0] = -1;

	while(1)
	{
		//选出d[u]最小的点
		mincost = INFTY;
		for(int i=0; i<n; i++)
		{
			if(color[i] != BLACK && mincost > d[i])
			{
				mincost = d[i];
				u = i;
			}
		}
		color[u] = BLACK;

		if(mincost == INFTY) break;

		for(int i=0; i<n; i++)
		{
			if(color[i] != BLACK && M[u][i] < INFTY)
			{
				if(d[u] + M[u][i] < d[i])
				{
					d[i] = d[u] + M[u][i];
					p[i] = u;
					color[i] = GRAY;
				}
			}
		}
	}
}

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

	dijkstra();

	for(int i=0; i<n; i++)
	{
		printf("%d %d\n", i, d[i]);
	}

	return 0;
}

C++: //Single Source Shortest Path I
#include <iostream>
#include <vector>
#include <climits>

using namespace std;

static const int N = 100;
static const int WHITE = 0;
static const int BLACK = 1;
//int colors[N], d[N];
//
//void dijkstra(vector<vector<int>> &W, int n) {
//    int u, mind;
//    for(int i = 0; i < n; i++) {
//        colors[i] = WHITE;
//        d[i] = INT_MAX;
//    }
//    d[0] = 0;
//    while(1) {
//        u = -1;
//        mind = INT_MAX;
//        for(int i = 0; i < n; i++) {
//            if(colors[i] == WHITE && d[i] < mind) {
//                u = i;
//                mind = d[i];
//            }
//        }
//        if(u == -1) break;
//        colors[u] = BLACK;
//        for(int i = 0; i < n; i++) {
//            if(W[u][i] != -1) {
//                d[i] = min(d[i], mind + W[u][i]);
//            }
//        }
//    }
//}
int d[N];

void dijkstra(vector<vector<int>> &W, int n) {
    int colors[n];
    for(int i=0; i<n; i++) {
        colors[i] = WHITE;
        d[i] = INT_MAX;
    }
    
    d[0] = 0;

    while(1) {
        int u = -1;
        int min_distance = INT_MAX;
        for(int i=0; i<n; i++) {
            if(colors[i] == BLACK) continue;
            if(d[i] < min_distance) {
                u = i;
                min_distance = d[i];
            }
        }
        if(u == -1) break;

        colors[u] = BLACK;
        for(int i=0; i<n; i++) {
            if(colors[i] == BLACK) continue;
            if(W[u][i] == -1) continue;
            d[i] = min(d[i], d[u] + W[u][i]);
        }
    }
}

int main() {
    int n;
    int u, k, v, c;
    cin >> n;
    vector<vector<int>> W(n, vector<int>(n));
    for(int i = 0; i < n; i++)
        for(int j = 0; j < n; j++)
            W[i][j] = -1;
    for(int i = 0; i < n; i++) {
        cin >> u >> k;
        for(int j = 0; j < k; j++) {
            cin >> v >> c;
            W[u][v] = c;
        }
    }

    dijkstra(W, n);

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

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 < 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;
}