Go: package main

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

const BIG_COST = 200000

const (
	ST_NOT_YET = iota
	ST_JOINED
)

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	nNodes := scanInt(sc)

	costs := make([][]int, nNodes)
	graph := make([][]int, nNodes)

	states := make([]int, nNodes)
	costSums := make([]int, nNodes)

	for i := 0; i < nNodes; i++ {
		costs[i] = make([]int, nNodes)
		costSums[i] = BIG_COST
	}

	for i := 0; i < nNodes; i++ {
		u := scanInt(sc)
		k := scanInt(sc)
		graph[u] = make([]int, k)
		for d := 0; d < k; d++ {
			v := scanInt(sc)
			graph[u][d] = v
			costs[u][v] = scanInt(sc)
		}
	}

	costSums[0] = 0
	for {
		minCost := BIG_COST
		var u int

		for i, cost := range costSums {
			if states[i] != ST_JOINED && cost < minCost {
				minCost = cost
				u = i
			}
		}

		if minCost == BIG_COST {
			break
		}

		states[u] = ST_JOINED

		for _, v := range graph[u] {
			cost := minCost + costs[u][v]
			if cost < costSums[v] {
				costSums[v] = cost
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i, cost := range costSums {
		fmt.Fprintf(w, "%d %d\n", i, cost)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

Python: n = int(input())

adj = [[False for j in range(n)] for i in range(n)]

for u in range(n):
    x = list(map(int, input().split()))
    for v, c in zip(x[2::2], x[3::2]):
        adj[u][v] = c

weights = [9900000] * n


def search(goal, path, weight):
    e = path[-1]
    if (e == goal) and (weight < weights[goal]):
        weights[goal] = weight
    elif weight < weights[goal]:
        for v, c in enumerate(adj[e]):
            if (v not in path) and (c is not False):
                path.append(v)
                weight += c
                search(goal, path, weight)
                weight -= c
                path.pop()


for i in range(n):
    search(i, [0], 0)

for v, w in enumerate(weights):
    print(v, w)

Python: #coding:utf-8
inf = 1000000
n = int(input())
M = [[inf for i in range(n)] for j in range(n)]
vwMtrx = []
for i in range(n):
    data = list(map(int,input().split()))
    u = data[0]
    k = data[1]
    col = []
    for j in range(0,2*k,2):
        v, w = data[j+2], data[j+3]
        M[u][v] = w
        col.append([v,w])
    vwMtrx.append(col)

def dijkstra(s):
    color = ["white" for i in range(n)]
    d = [inf for i in range(n)]
    p = [-1 for i in range(n)]
    d[s] = 0
    Q = [[s,0]]
    while Q != []:
        u = min(Q, key=lambda x:x[1])
        Q = [List for List in Q if List != u]
        u = u[0]
        color[u] = "black"

        vwList = vwMtrx[u]
        
        for vw in vwList:
            v,w = vw[0],vw[1]
            if color[v] != "black" and M[u][v] != inf:
                if d[u] + M[u][v] < d[v]:
                    d[v] = d[u] + M[u][v]
                    p[v] = u
                    color[v] = "gray"
                    Q.append([v, d[v]])

    return d

dList = dijkstra(0)
for i, d in enumerate(dList):
    print(i,d)

Python: # 単一始点最短経路 Single source shortest path I

INFTY = 2000000000

n = int(input())
M = [[INFTY for i in range(n)] for i in range(n)]
for i in range(n):
    dat = [int(i) for i in input().split()]
    for j in range(1, dat[1] + 1):
        M[dat[0]][dat[2 * j]] = dat[2 * j + 1]

col = [-1 for i in range(n)]
d = [INFTY for i in range(n)]
p = [-1 for i in range(n)]

d[0] = 0

while True:
    mincost = INFTY
    for i in range(n):
        if col[i] != 1 and d[i] < mincost:
            mincost = d[i]
            u = i
    
    if mincost == INFTY:
        break
    
    col[u] = 1
    
    for v in range(n):
        if col[v] != 1 and M[u][v] != -1:
            if d[u] + M[u][v] < d[v]:
                d[v] = d[u] + M[u][v]
                p[v] = u
                col[v] = 0

for i in range(n):
    print(i, d[i])

Python: def dijkstra(n):
    inf = 10 ** 6 + 1
    dist = [0] + [inf] * (n - 1)
    visited = [False] * n

    while not all(visited):
        dmin = inf
        for i, (d, v) in enumerate(zip(dist, visited)):
            if dmin > d and not v:
                u = i

        visited[u] = True
        for (v, c) in edge[u]:
            if dist[v] > dist[u] + c:
                dist[v] = dist[u] + c
    return dist

n = int(input())
edge = [[]] * n
for _ in range(n):
    l = list(map(int, input().split()))
    edge[l[0]] = (e for e in zip(l[2::2], l[3::2]))
for i, c in enumerate(dijkstra(n)):
    print(i, c)

Python: #coding:utf-8
def Dijkestra(G,n):
    d=[100000000000]*n
    pi=[None]*n
    d[0]=0
    C=[]
    for i in range(n):
        C.append(i)
    
    while len(C)!=0:
        u=C[0]
        for i in range(1,len(C)):
            if d[u]>d[i]:
                u=C[i]
        C.remove(u)
        for i in range(len(G[u])):
            if G[u][i]==-1:
                continue
            elif d[i]>d[u]+G[u][i]:
                d[i]=d[u]+G[u][i]
                pi[i]=u
                        
    for i in range(n):
        print(i,d[i])
    

if __name__=="__main__":
    n=int(input())
    G=[]
    for i in range(n):
        a=[]
        ele=list(map(int,input().split()))
        k=ele[1]
        t=ele[2:]
        v=c=[]
        for j in range(k):
            v=v+[t[2*j]]
            c=c+[t[2*j+1]]
        for j in range(n):
            if j in v:
                a.append(c[v.index(j)])
            else:
                a.append(-1)
        G.append(a)
    Dijkestra(G,n)

Python: """Shortest Path"""

import sys
import os
import pprint

#fd = os.open('ALDS1_12_B.txt', os.O_RDONLY)
#os.dup2(fd, sys.stdin.fileno())

level = True
def debug(v):
    if level:
        print(v)

n = int(input())
INF = float('inf')
W = [[INF for j in range(n)] for i in range(n)]

for _ in range(n):
    l = list(map(int, input().split()))
    node_index = l[0]
    num = l[1]
    data = l[2:]
    for i in range(num):
        node = data[i*2]
        weight = data[i*2+1]
        W[node_index][node] = weight

d = [INF] * n
visited = [False] * n
parent = [None] * n

# root
d[0] = 0

while True:
    min_dist = INF
    min_index = None
    for i in range(n):
        if not visited[i] and d[i] < min_dist:
            min_dist = d[i]
            min_index = i

    if min_index is None:
        break

    # accept
    visited[min_index] = True

    for i in range(n):
        if not visited[i] and d[i] > d[min_index] + W[min_index][i]:
            d[i] = d[min_index] + W[min_index][i]
            parent[i] = min_index
for i in range(len(d)):
    s = '{} {}'.format(i, d[i])
    print(s)

Python: #coding:utf-8
def Dijkestra(G,n):
    d=[100000000000]*n
    pi=[None]*n
    d[0]=0
    C=[]
    for i in range(n):
        C.append(i)
    
    while len(C)!=0:
        u=C[0]
        for i in range(1,len(C)):
            if d[u]>d[C[i]]:
                u=C[i]
        C.remove(u)
        for i in range(len(G[u])):
            if G[u][i]==-1:
                continue
            elif d[i]>d[u]+G[u][i]:
                d[i]=d[u]+G[u][i]
                pi[i]=u                
    for i in range(n):
        print(i,d[i])
    

if __name__=="__main__":
    n=int(input())
    G=[]
    for i in range(n):
        a=[]
        ele=list(map(int,input().split()))
        k=ele[1]
        t=ele[2:]
        v=c=[]
        for j in range(k):
            v=v+[t[2*j]]
            c=c+[t[2*j+1]]
        for j in range(n):
            if j in v:
                a.append(c[v.index(j)])
            else:
                a.append(-1)
        G.append(a)
    Dijkestra(G,n)