Happy Number
思路一: happy number 的结果完全分类,就两种情况
- 最后的值为 1
- 进入循环(用 map 记录)
public boolean isHappy(int n) {
Set<Integer> set = new HashSet<>();
while (true) {
int sum = 0;
while (n >= 1) {
sum += (n % 10) * (n % 10);
n /= 10;
}
if (sum == 1) return true;
n = sum;
if (set.contains(sum)) {
return false;
} else {
set.add(sum);
}
}
}
标签:10,202,return,int,sum,set,easy,leetcode
From: https://www.cnblogs.com/iyiluo/p/16804870.html