LeetCode202——Happy Number快乐数

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: 19 is a happy number

12 + 92 =
82
82 + 22 =
68
62 + 82 =
100

12 + 02 +
02 = 1

实现：

bool isHappy(int n) {

vector<int> result;

int val = getSquareSum(n);

while (val != 1) {

if (std::find(result.begin(), result.end(), val) != result.end()) {

return false;

}

result.push_back(val);

val = getSquareSum(val);

}

return true;

}

int getSquareSum(int n) {

int val = 0;

while (n) {

int rem = n%10;

val += rem*rem;

n = n / 10;

}

return val;

}