Li Kou daily question - day 31 -202 Happy number

2022.6.30 Did you brush the questions today ？

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subject ：

Write an algorithm to judge a number n Is it a happy number .

「 Happy number 」  Defined as ：

For a positive integer , Replace the number with the sum of the squares of the numbers in each of its positions .
Then repeat the process until the number becomes 1, It could be Infinite loop But it doesn't change 1.
If this process The result is  1, So this number is the happy number .
If n yes Happy number Just go back to true ; No , Then return to false .

analysis ：

Give you a number , You need to take it apart in this way , Then count each square , Add up all the numbers , Finally, judge whether this number is =1, by 1 Is the number of happy , Not for 1 It's not .

Ideas ： Use numbers while In this way, separate and average , Finally, judge the result .

analysis ：

class Solution {
public:
    bool isHappy(int n) {
        
        for (int i = 0; i < 100; i++)
        {
            int ans = 0;
            while (n > 0)
            {
                ans += (n % 10) * (n % 10);
                n = n / 10;
            }
            n = ans;
            if (n == 1)
                return true;
        }
        return false;
    }
};