为什么py会有一个re点呢？各位大佬求助

import collections

n = int(input())
nxs = collections.defaultdict(list)
dp = [[0]*2 for _ in range(n)]
flag = [1] * n
for _ in range(n):
    nums = list(map(int, input().split()))
    p, s = nums[0], nums[1]
    for i in range(s):
        nxs[p].append(nums[i+2])
        flag[nums[i+2]] = 0
def dfs(i):
    global dp
    if i in nxs:
        for j in nxs[i]:
            dfs(j)
            dp[i][0] += dp[j][1]
            dp[i][1] += min(dp[j][0], dp[j][1])
    dp[i][1] += 1

for i in range(n):
    if flag[i] == 1:
        dfs(i)
        print(min(dp[i][1], dp[i][0]))
        break

go没这个问题

func timu4() {
    var n int
    fmt.Scan(&n)
    nxs := make(map[int][]int, n)
    dp := make([][2]int, n)
    flag := make([]int, n)
    for i := 0; i < n; i++ {
        flag[i] = 1
    }
    for i := 0; i < n; i++ {
        var point int
        var length int
        fmt.Scan(&point, &length)
        var a int
        tmp := make([]int, length)
        for j := 0; j < length; j++ {
            fmt.Scan(&a)
            tmp[j] = a
            flag[a] = 0
        }
        nxs[point] = tmp
    }
    var dfs func(int)
    dfs = func(i int) {

        for _, j := range nxs[i] {
            dfs(j)
            dp[i][1] += min(dp[j][0], dp[j][1])
            dp[i][0] += dp[j][1]
        }
        dp[i][1] += 1
    }
    for i := 0; i < n; i++ {
        if flag[i] == 1 {
            dfs(i)
            fmt.Println(min(dp[i][0], dp[i][1]))
            break
        }
    }
}