Happy number
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: is a happy number
- 12 + 92 = 82
- 82 + 22 = 68
- 62 + 82 = 100
- 12 + 02 + 02 = 1
Direct simulation.
Class Solution {public: bool Ishappy (int n) { if (n = = 1) return true; int m; map<int,int>a; while (n! = 1) { if (a[n] = = 1) break; A[n] = 1; m = 0; while (n) { m + = (n%10) * (N%10); n = n/10; } n = m; if (n = = 1) return true; } return false; }};
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Leetcode-202-happy number