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 <stdio.h>
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];
int d[n];

void dijkstra(int s) {
    int p[n];
    int color[n];
    
    for(int i=0; i<n; i++) {
        color[i] = WHITE;
        d[i] = INFTY;
        p[i] = -1;
    }
    
    d[s] = 0;
    
    while(1) {
        int u;
        int mincost = INFTY;
        for (int i=0; i<n; i++) {
            if (color[i] != BLACK && d[i] < mincost) {
                mincost = d[i];
                u = i;
            }
        }
        
        if (mincost == INFTY) break;
        
        color[u] = BLACK;
        
        for (int v=0; v<=n; v++) {
            if (color[v] != BLACK && M[u][v] != INFTY) {
                if(d[u] + M[u][v] < d[v]) {
                    d[v] = d[u] + M[u][v];
                    p[v] = u;
                    color[v] = GRAY;
                }
            }
        }
    }
}

int main() {
    scanf("%d", &n);
    for (int i=0; i<n; i++) {
        for (int j=0; j<n; j++) {
            int tmp;
            scanf("%d", &tmp);
            M[i][j] = (tmp == -1) ? INFTY : tmp;
        }
    }
    
    dijkstra(0);
    
    for(int i=0; i<n; i++) {
        printf("%d %d\n", i, d[i]);
    }
    
    return 0;
}

C++: #include <cstdio>
static const int INFTY = (1 << 21);
static const int WHITE = 0;
static const int GRAY = 1;
static const int BLACK = 2;

int n, **M;
int *d;

void dijkstra() {
    int u, minv;
    int d[n], color[n];

    for (int i = 0; i < n; i++) {
        d[i] = INFTY;
        color[n] = WHITE;
    }
    d[0] = 0;

    while (1) {
        u = -1;
        minv = INFTY;
        for (int i = 0; i < n; i++) {
            if (color[i] != BLACK && d[i] < minv) {
                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[u] + M[u][v] < d[v]) {
                    d[v] = d[u] + M[u][v];
                    color[v] = GRAY;
                }             
            }
        }
    }
    
    for (int i = 0; i < n; i++) {
        printf("%d %d", i, d[i]);
        if (i != n - 1) { printf("\n"); }
    }
}

int main() {
    scanf("%d", &n);

    M = new int*[n];
    for (int i = 0; i < n; i++) {
        M[i] = new int[n];
        for (int j = 0; j < n; j++) {
            M[i][j] = INFTY;
        }
    }

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

    dijkstra();

    return 0;
}

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 < MAX; 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;
}