Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

const (
	MAX_N      = 100
	MAX_WEIGHT = 100000
)

type Edge struct {
	start  int
	end    int
	weight int
}

type ShortestInfo struct {
	edges    []Edge
	shortest 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{1}, shortestList, adjacentMatrix)
	for _, v := range shortestList {
		fmt.Printf("%d %d\n", v.getEnd()-1, v.shortest)
	}
}

func (si ShortestInfo) getEnd() int {
	if len(si.edges) == 0 {
		return 1
	} else {
		return si.edges[len(si.edges)-1].end
	}
}

func createAdjacentMatrix(n int, sc *bufio.Scanner) ([][]int, error) {
	adjacentMatrix := make([][]int, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			return nil, err
		}
		adjacentMatrix[id] = make([]int, n)
		for j := 0; j < n; j++ {
			adjacentMatrix[id][j] = -1
		}
		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][v] = c
		}
	}
	return adjacentMatrix, nil
}

func sssp(nodeStack []int, shortestList []ShortestInfo, adjacentMatrix [][]int) {
	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-1]
}

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-1] = shortestInfo
}

func findAdjacents(currentNode int, adjacentMatrix [][]int) []Edge {
	adjacents := adjacentMatrix[currentNode-1]
	edges := []Edge{}
	for i, v := range adjacents {
		if v > 0 {
			edges = append(edges, Edge{start: currentNode, end: i + 1, weight: v})
		}
	}
	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 ll = long long;
const ll INF = 1e16;
const ll mod = 1000000007;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
template<class T> inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template<class T> inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
int ctoi(char c) {
  if (c >= '0' && c <= '9') {
    return c - '0';
  }
  return 0;
}
ll factorial(ll n) {
  if (n == 1) {
    return 1;
  }
  ll ans = factorial(n-1);
  return ans*n;
}
ll gcd(ll a, ll b) {
  if (a < b) {
    ll tmp = a;
    a = b;
    b = tmp;
  }
  ll r = a%b;
  while(r != 0) {
    a = b;
    b = r;
    r = a%b;
  }
  return b;
}
ll lcm(ll a, ll b) {
  return (a/gcd(a, b))*b;
}
bool prime(ll n) {
  if (n == 1) {
    return false;
  } else {
    for (ll i = 2; i <= (ll)pow(n, 0.5); i++) {
      if (n%i == 0) return false;
    }
  }
  return true;
}
ll RepeatSquaring(ll n, ll p, ll m) {
  if (p == 0) return 1;
  if (p%2 == 0) {
    ll t = RepeatSquaring(n, p/2, m);
    return (t*t)%m;
  }
  return (n*RepeatSquaring(n, p-1, m))%m;
}

vector <ll> color(100, 0);
vector <vector <ll>> m(100, vector <ll> (100, -1));
vector <ll> d(100, INF);
vector <ll> p(100, -1);

void dijkstra(ll n) {
  d.at(0) = 0;
  p.at(0) = -1;
  while (true) {
    ll mincost = INF;
    ll u;
    rep(i, n) {
      if (color.at(i) != 2 && d.at(i) < mincost) {
        mincost = d.at(i);
        u = i;
      }
    }
    if (mincost == INF) break;
    color.at(u) = 2;
    rep(i, n) {
      if (color.at(i) != 2 && m.at(u).at(i) != -1) {
        if (d.at(u)+m.at(u).at(i) < d.at(i)) {
          d.at(i) = d.at(u) + m.at(u).at(i);
          p.at(i) = u;
          color.at(i) = 1;
        }
      }
    }
  }
  return;
}

int main() {
  ll n;
  cin >> n;
  rep(i, n) {
    ll u, k;
    cin >> u >> k;
    rep(j, k) {
      ll v, c;
      cin >> v >> c;
      m.at(i).at(v) = c;
    }
  }
  dijkstra(n);
  rep(i, n) {
    cout << i << ' ' << d.at(i) << endl;
  }
}

C++: #include "bits/stdc++.h"
#pragma GCC optimize("Ofast")

// Begin {{{
using namespace std;

#ifndef DEBUG
#define dump(...)
#endif

template <class A, class B> inline bool chmax(A &a, const B &b) { return b > a && (a = b, true); }
template <class A, class B> inline bool chmin(A &a, const B &b) { return b < a && (a = b, true); }

template <class T>
inline vector<T> make_v(const T &initvalue, size_t sz) {
    return vector<T>(sz, initvalue);
}

template <class T, class... Args>
inline auto make_v(const T &initvalue, size_t sz, Args... args) {
    return vector<decltype(make_v<T>(initvalue, args...))>(sz, make_v<T>(initvalue, args...));
}

constexpr int INF = 0x3f3f3f3f;
constexpr int64_t LINF = 0x3f3f3f3f3f3f3f3fLL;
// }}} End

using pii = pair<size_t, size_t>;

vector<pii> G[int(1e2)]; // {node, cost}
size_t N;

vector<size_t> cost(int(1e2), INF);

void dijkstra() {
    priority_queue<pii, vector<pii>, greater<>> que; // {cost, node}
    cost[0] = 0;
    que.emplace(0, 0);

    while (!que.empty()) {
        size_t nowcost = que.top().first;
        size_t nownode = que.top().second;
        que.pop();
        if (cost[nownode] < nowcost) continue;

        for (auto next: G[nownode]) {
            if (chmin(cost[next.first], cost[nownode] + next.second)) {
                que.emplace(cost[next.first], next.first);
            }
        }
    }
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    size_t N; cin >> N;

    for (size_t i = 0; i < N; ++i) {
        size_t u, k; cin >> u >> k;
        for (size_t j = 0; j < k; ++j) {
            size_t v, c; cin >> v >> c;
            G[u].emplace_back(v, c);
        }
    }

    dijkstra();

    for (size_t node = 0; node < N; ++node) {
        cout << node << " " << cost[node] << "\n";
    }

    return 0;
}