Find the Number Occurring Odd Number of Times

最新推荐文章于 2022-05-15 08:57:09 发布

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本博客介绍了一个算法，用于在给定数组中找到出现奇数次的整数，仅需O(n)时间复杂度和常数空间。通过执行位操作XOR运算，最终得到所需整数。

reference:

http://www.geeksforgeeks.org/find-the-number-occurring-odd-number-of-times/

Problem Definition:

Given an array of positive integers. All numbers occur even number of times except one number which occurs odd number of times. Find the number in O(n) time & constant space.

Solution:

Do bitwise XOR of all the elements. Finally we get the number which has odd occurrences.

Code:

int getOddOccurrence(int ar[], int ar_size)
{
     int i;
     int res = 0; 
     for (i=0; i < ar_size; i++)     
        res = res ^ ar[i];
      
     return res;
}