Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Node struct {
	cost int
	done bool
}

type Edge struct {
	to, cost int
}

const INF = 1 << 60

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	nodes := make([]Node, N)
	for i := 0; i < N; i++ {
		nodes[i].cost = INF
	}
	E := make([][]Edge, N)
	for i := 0; i < N; i++ {
		id, k := sc.nextInt(), sc.nextInt()
		for j := 0; j < k; j++ {
			to, cost := sc.nextInt(), sc.nextInt()
			E[id] = append(E[id], Edge{to, cost})
		}
	}
	nodes[0].cost = 0
	for {
		cur := 0
		minCost := INF
		for i := 0; i < N; i++ {
			n := nodes[i]
			if !n.done && n.cost < minCost {
				cur = i
				minCost = n.cost
			}
		}
		if minCost == INF {
			break
		}
		nodes[cur].done = true
		for i := 0; i < len(E[cur]); i++ {
			to, cost := E[cur][i].to, E[cur][i].cost+nodes[cur].cost
			if !nodes[to].done && cost < nodes[to].cost {
				nodes[to].cost = cost
			}
		}
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i, nodes[i].cost)
	}
	wtr.Flush()
}

C++: #include <cstdio>
#include <vector>
#include <algorithm>
#include <queue>

using namespace std;

using Weight=int;
using DArray=vector<Weight>;
using DMatrix=vector<DArray>;

static const Weight INF=1<<29;

struct Edge {
    size_t src, dst;
    Weight weight;
    Edge() {}
    Edge(size_t src, size_t dst, Weight weight=1):
        src(src), dst(dst), weight(weight)
    {}
};

bool operator<(const Edge &e, const Edge &f) {
    if (e.weight != f.weight) {
        return e.weight > f.weight;
    } else {
        return e.src!=f.src? e.src<f.src : e.dst<f.dst;
    }
}

using Edges=vector<Edge>;
using Vertex=vector<Edge>;
using Graph=vector<Vertex>;

void join(Graph &g, size_t s, size_t d, Weight w=1) {
    // non-directed
    g[s].push_back(Edge(s, d, w));
    g[d].push_back(Edge(d, s, w));
}

void connect(Graph &g, size_t s, size_t d, Weight w=1) {
    // directed
    g[s].push_back(Edge(s, d, w));
}

template <class T>
using lp_queue=priority_queue<T, deque<T>, greater<T>>;

template <typename T, typename U=size_t>
union raw_cast {
    public:
        constexpr raw_cast(T t): _t(t) {}
        operator U() const {
            return _u;
        }

    private:
        T _t;
        U _u;
};

size_t bsr(size_t n) {
    /* Bit scan reverse */
    // logarithmus binarius
    if (!n) return -1;

    size_t res;
    for (res=0; n>>=1; ++res)
        if (!n) return res;

    return res;
}

template <class Index, class T, size_t bucketSize=sizeof(Index)<<3>
struct RadixHeap {
    vector<pair<Index, T>> v[bucketSize|1];
    Index last;
    size_t size_;
    RadixHeap(): last(0), size_(0) {}
    void push(Index n, T t) {
        if (last > n) return;

        ++size_;
        size_t idx=raw_cast<Index>(n);
        idx ^= raw_cast<Index>(last);
        v[bsr(idx)+1].push_back(make_pair(n, t));
    }
    void push(pair<Index, T> p) {
        push(p.first, p.second);
    }
    void pop() {
        if (!size_) return;
        if (!v[0].size()) {
            size_t i; for (i=1; !v[i].size(); ++i);
            last = min_element(v[i].begin(), v[i].end())->first;
            for (const pair<Index, T> &p: v[i]) {
                size_t idx=raw_cast<Index>(p.first);
                idx ^= raw_cast<Index>(last);
                v[bsr(idx)+1].push_back(p);
            }

            v[i].clear();
        }
        --size_;
        v[0].pop_back();
    }
    pair<Index, T> top() {
        if (!size_) return pair<Index, T>();
        if (!v[0].size()) {
            size_t i; for (i=1; !v[i].size(); ++i);
            last = min_element(v[i].begin(), v[i].end())->first;
            for (const pair<Index, T> &p: v[i]) {
                size_t idx=raw_cast<Index>(p.first);
                idx ^= raw_cast<Index>(last);
                v[bsr(idx)+1].push_back(p);
            }

            v[i].clear();
        }
        return v[0].back();
    }
    size_t size() {
        return size_;
    }
    bool empty() {
        return !size_;
    }
    void clear() {
        last = size_ = 0;
        for (size_t i=0; i<=bucketSize; ++i)
            v[i].clear();
    }
};

vector<Weight> shortest_distance(const Graph &g, size_t s) {
    /* Dijkstra */
    size_t V=g.size();
    vector<Weight> d(V, INF); d[s]=0;

    RadixHeap<Weight, size_t> q; q.push(0, s);
    while (!q.empty()) {
        pair<Weight, size_t> p=q.top(); q.pop();
        size_t v=p.second;
        if (d[v] < p.first) continue;

        for (const Edge &e: g[v])
            if (d[e.dst] > d[v] + e.weight) {
                d[e.dst] = d[v] + e.weight;
                q.push(d[e.dst], e.dst);
            }
    }
    return d;
}

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

    Graph g(n);
    for (size_t i=0; i<n; ++i) {
        size_t u, k;
        scanf("%zu %zu", &u, &k);

        for (size_t j=0; j<k; ++j) {
            size_t c;
            Weight v;
            scanf("%zu %d", &c, &v);

            connect(g, u, c, v);
        }
    }

    vector<Weight> d=shortest_distance(g, 0);
    for (size_t i=0; i<n; ++i)
        printf("%zu %d\n", i, d[i]);

    return 0;
}

C++: #include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
const int MAX=105;
const int INF= 1<<30;
int M[MAX][MAX],n,d[MAX],p[MAX],vis[MAX];
void init(){
	for(int i=0;i<n;i++){
		d[i]=INF;
		p[i]=-1;
		vis[i]=0;
	}
	d[0]=0;
}
void dijkstra(){
	init();
	while (true){
		int u=-1;
		int minCost=INF;
		for(int i=0;i<n;i++){
			if(!vis[i] && d[i]<minCost){
				u=i;
				minCost=d[i];
			}
		}
		if(u==-1)break;
		vis[u]=1;
		for(int i=0;i<n;i++){
			if(!vis[i] && M[u][i]!=-1 &&M[u][i]+d[u]<d[i]){
				d[i]=M[u][i]+d[u];
				p[i]=u;
			}
		}
	}
}
int main(){
	cin>>n;
	memset(M,-1,sizeof(M));
	for(int i=0;i<n;i++){
		int u,k,v,c;
		cin>>u>>k;
		for(int j=0;j<k;j++){
			cin>>v>>c;
			M[u][v]=c;
		}
	}
	dijkstra();
	for(int i=0;i<n;i++){
		printf("%d %d\n",i,d[i]);
	}
	return 0;
}