0202. Happy Number

# 202. Happy Number#

## 题目 #

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 1:

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

``````

## 代码 #

``````
package leetcode

func isHappy(n int) bool {
record := map[int]int{}
for n != 1 {
record[n] = n
n = getSquareOfDigits(n)
for _, previous := range record {
if n == previous {
return false
}
}
}
return true
}

func getSquareOfDigits(n int) int {
squareOfDigits := 0
temporary := n
for temporary != 0 {
remainder := temporary % 10
squareOfDigits += remainder * remainder
temporary /= 10
}
return squareOfDigits
}

``````

Apr 8, 2023