[LeetCode]202.Happy Number

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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

思路

無

代碼

/*---------------------------------------------------------*   日期：2015-04-22*   SJF0115*   題目: 202.Happy Number*   網址：https://leetcode.com/problems/happy-number/*   結果：AC*   來源：LeetCode*   部落格：------------------------------------------------------------*/#include <iostream>#include <vector>#include <algorithm>using namespace std;class Solution {public:    bool isHappy(int n) {        if(n == 1){            return true;        }//if        if(n == 0){            return false;        }//if        return Recursion(n);    }private:    vector<int> visited;    bool Recursion(int n){        if(n == 1){            return true;        }//if        int num = n;        int tmp,value = 0;        while(num){            tmp = num % 10;            value += tmp * tmp;            num /= 10;        }//while        // 判斷是否形成圈        vector<int>::iterator result = find(visited.begin(),visited.end(),value);        if(result != visited.end()){            return false;        }//if        visited.push_back(value);        return Recursion(value);    }};int main(){    Solution solution;    int n = 2;    if(solution.isHappy(n)){        cout<<n<<" is Happy Number"<<endl;    }//if    else{        cout<<n<<" is not Happy Number"<<endl;    }    return 0;}

已耗用時間

[LeetCode]202.Happy Number