您當(dāng)前位置：首頁 > php開源 > 綜合技術(shù) > LeetCode Happy Number

LeetCode Happy Number

來源：程序員人生發(fā)布時間：2015-06-23 08:16:23 閱讀次數(shù)：3325次

1. 題目

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: 19 is a happy number

1² + 9² = 82
8² + 2² = 68
6² + 8² = 100
1² + 0² + 0² = 1

2.解題方案

class Solution { public: bool isHappy(int n) { if(n < 1){ return false; } if(n == 1){ return true; } unordered_set<int> showNums; showNums.insert(n); while(true){ int sum = 0; while(n != 0){ int oneDigital = n % 10; n = n / 10; sum = sum + oneDigital * oneDigital; } if(sum == 1){ return true; }else{ if(showNums.find(sum) == showNums.end()){ showNums.insert(sum); }else{ return false; } } n = sum; } } };

思路：用求余和除以10得到每位數(shù)，相加進(jìn)行判斷。這里還用了1個set來存儲已出現(xiàn)的數(shù)字，如果重復(fù)了，說明就不是1個happy number。

http://www.waitingfy.com/archives/1678

生活不易，碼農(nóng)辛苦
如果您覺得本網(wǎng)站對您的學(xué)習(xí)有所幫助,可以手機(jī)掃描二維碼進(jìn)行捐贈
程序員人生