leetcode1088

参考了CSDN上一位博主提供的C++的代码：

class Solution {
public:
  int confusingNumberII(int N) {
    n = N;
    ans = 0;
    search(0);
    return ans;
  }
private:
  int n, ans;
  void search(long long num) {
    if (num > n) return;
    if (num) {
      if (rotate(num) != num) ++ ans;
    }
    if (num) search(num * 10);
    search(num * 10 + 1);
    search(num * 10 + 6);
    search(num * 10 + 8);
    search(num * 10 + 9);
  }
  long long rotate(long long x) {
    long long y = 0;
    for (; x; x /= 10) {
      int k = x % 10;
      switch (k) {
        case 6: k = 9; break;
        case 9: k = 6; break;
      }
      y = y * 10 + k;
    }
    return y;
  }
};

我尝试转换成python，但是却超时了：

class Solution:
    def __init__(self):
        self.n = 0
        self.ans = 0

    def confusingNumberII(self, N: int) -> int:
        self.n = N
        self.searchNumber(0)
        return self.ans

    def searchNumber(self,num):
        if num > self.n:
            return
        #if self.confusingNumber(num):
        if num != 0 and self.rotate(num) != num:
            self.ans += 1
            #print(str(self.ans) +":"+ str(num))
        if num != 0:
            self.searchNumber(num * 10)
        self.searchNumber(num * 10 + 1)
        self.searchNumber(num * 10 + 6)
        self.searchNumber(num * 10 + 8)
        self.searchNumber(num * 10 + 9)

    def rotate(self,x):
        y = 0
        while x != 0:
            k = x % 10
            if k == 6:
                k = 9
            elif k == 9:
                k = 6
            y = y * 10 + k
            x = x // 10
        return y

超时的测试用例：1000000000，答案：1950627，python在我本机执行时间：11.3s。

目前没想到解决办法。