# [LeetCode]202. Happy Number（平衡二叉树 哈希表）

2021-07-20 03:51:26 李响Superb

Write an algorithm to determine if a number is “happy”.

A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers.
Example:

``````Input: 19
Output: true
Explanation:
12 + 92 = 82
82 + 22 = 68
62 + 82 = 100
12 + 02 + 02 = 1

```

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``````bool isHappy(int n) {//0ms
if(n == 0) return 0;
int squares = n;
while(squares >= 10){
int temp = 0;
while(squares) {
temp += (squares%10)*(squares%10);
squares = squares/10;
}
squares = temp;
}

if(squares == 1 || squares == 7)
return true;
else
return false;
}
```

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https://blog.51cto.com/u_14013325/2891921