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 and replace the number by the Sum of the squares of its digits, and repeat the process until the number equals 1 (where it would stay), or it loops Endl essly in a cycle which does not include 1. Those numbers for which this process ends in 1 is happy numbers.
Example:19 is a happy number
- 12 + 92 = 82
- 82 + 22 = 68
- 62 + 82 = 100
- 12 + 02 + 02 = 1
Set the loop, if the last cannot get 1, there must be a loop so that the resulting value is equal to the previously generated value.
The *JS array does not have a built-in contains/include function and needs to be added yourself.
Array.prototype.contains =function(x) { for(varIinch This) if( This[I] = =x)return true return false}varIshappy =function(n) {vartemp = [] vars =n.tostring () while(true){ varsum = 0 for(vari=0;i<s.length;i++) Sum+ = s[i]*S[i]if(Sum = = 1) return true Else if(Temp.contains (sum))return falseTemp.push (sum) s=sum.tostring ()}}
Leetcode 202 Happy Number