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>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <cmath>
#include <cstdlib>
using namespace std;
#define Test
const int MAX = 110000;
const int INF = 10000000;
vector<pair<int, int> > G[MAX];
int n;
int dis[MAX];
int vis[MAX];

void dij(int p) {
    for (int i = 0; i < n; i++) dis[i] = INF;
    memset(vis, false, sizeof(vis));
    dis[p] = 0;
    priority_queue<pair<int, int>, vector<pair<int,int>>, greater<pair<int,int>>> pq;
    pq.push(make_pair(0, p));
    while (!pq.empty()) {
        pair<int, int> pr = pq.top();
        pq.pop();
        int point = pr.second;
        if (vis[point]) continue;
        dis[point] = pr.first;
        vis[point] = true;
        for (int i = 0; i < G[point].size(); i++) {
            int pt = G[point][i].second;
            int v = G[point][i].first;
            if (!vis[pt] && dis[pt] > dis[point]+v) {
                dis[pt] = dis[point] + v;
                pq.push(make_pair(dis[pt], pt));
            }
        }
    }
}

int main() {
    //freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        int p, k;
        scanf("%d %d", &p, &k);
        while (k--) {
            int v, c;
            scanf("%d %d", &v, &c);
            G[p].push_back(make_pair(c, v));
        }
    }
    dij(0);
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i, dis[i]);
    }
    return 0;
}

C++: #include <cstdio>
#include <iostream>
using namespace std;

static const int MAX_NUM   = 101;
static const int NIL       = 100001;
static const int NO_VISIT  = 0;
static const int NOW_VISIT = 1;
static const int END_VISIT = 2;

void SSSP(int *pMatrix, int num)
{
    int i;
    int mincost;
    int target;
    int lcost[MAX_NUM];
    int parent[MAX_NUM];
    int state[MAX_NUM];
    int *pList;

    for (i = 0; i < num; i++) {
        lcost[i]  = NIL;
        parent[i] = -1;
        state[i]  = NO_VISIT;
    }

    lcost[0]  = 0;
    parent[0] = 0;
    state[0]  = NOW_VISIT;

    for (;;) {
        mincost   = NIL;
        for (i = 0; i < num; i++) {
            if ((lcost[i] < mincost) && (state[i] != END_VISIT)) {
                target = i;
                mincost = lcost[i];
            }
        }
        if (mincost == NIL) {
            break;
        }

        state[target] = END_VISIT;
        pList = pMatrix + MAX_NUM * target;
        for (i = 0; i < num; i++) {
            if ((*(pList + i) + lcost[target]) < lcost[i]) {
                lcost[i]  = *(pList + i) + lcost[target];
                state[i]  = NOW_VISIT;
                parent[i] = target;
            }
        }
    }

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

    return;
}

int main(void)
{
    int i, j;
    int num;
    int tmp;
    int target, elem, cost;
    int matrix[MAX_NUM][MAX_NUM];

    scanf("%d", &num);
    for (i = 0; i < num; i++) {
        for (j = 0; j < num; j++) {
            matrix[i][j] = NIL;
        }
    }

    for (i = 0; i < num; i++) {
        scanf("%d %d", &target, &tmp);
        for (j = 0; j < tmp; j++) {
            scanf("%d %d", &elem, &cost);
            matrix[target][elem] = cost;
        }
    }

    SSSP(&matrix[0][0], num);

    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
static const int INF   = (1 << 21);
static const int WHITE = 0;
static const int GRAY  = 1;
static const int BLACK = 2;
static const int NIL   = -1;
static const int MAX   = 100;

int n;
vector<vector<int>> M(MAX, vector<int>(MAX, NIL));

void dijstra(int s) {
  vector<int> color(n, WHITE);
  vector<int> d(n, INF);
  vector<int> p(n);
  d[s] = 0;
  p[s] = NIL;

  while (true) {
    int u       = 0;
    int mincost = INF;
    for (int i = 0; i < n; i++) {
      if (color[i] != BLACK && d[i] < mincost) {
        mincost = d[i];
        u       = i;
      }
    }
    if (mincost == INF) { break; }

    color[u] = BLACK;

    for (int v = 0; v < n; v++) {
      if (color[v] != BLACK && M[u][v] != NIL) {
        if (d[u] + M[u][v] < d[v]) {
          d[v]     = d[u] + M[u][v];
          p[v]     = u;
          color[v] = GRAY;
        }
      }
    }
  }
  int res = 0;
  for (int i = 0; i < n; i++) {
    cout << i << " " << d[i] << endl;
  }
}

int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    int id, k;
    cin >> id >> k;
    for (int j = 0; j < k * 2; j += 2) {
      int v, c;
      cin >> v >> c;
      M[id][v] = c;
    }
  }
  dijstra(0);
}