leetcode算法：202 快乐数(暴力法，hashset)

class Solution:
    def isHappy(self, n: int) -> bool:
        
        for i in range(100):
            ans =0
            while n>0:
                ans += (n%10)*(n%10)
                n //=10
            n=ans
            if n==1:
                return True
        return False

 

def isHappy(self, n: int) -> bool:

    def get_next(n):
        total_sum = 0
        while n > 0:
            n, digit = divmod(n, 10)
            total_sum += digit ** 2
        return total_sum

    seen = set()
    while n != 1 and n not in seen:
        seen.add(n)
        n = get_next(n)

    return n == 1

    def isHappy( n: int) -> bool:
        def fun(n):
            res=0
            while(n):
                tmp=n%10
                res+=pow(tmp,2)
                n=n//10
            return res
        nums=[]
        nums.append(n)
        print(nums)
        while(n):
            n=fun(n)
            print(n)
            if n==1:
                return True
            if n in nums:
                return False
            nums.append(n)
            print(nums)
isHappy(19)

class Solution:
    def isHappy(self, n: int) -> bool:
        s = str(n)
        if len(s) == 1 and int(s[0]) == 4:
            return False
        sum_num = 0
        for i in range(len(s)):
            sum_num += int(s[i]) ** 2
        if sum_num == 1:
            return True
        return self.isHappy(sum_num)