Find the Number Occurring Odd Number of Times

最新推荐文章于 2022-05-15 08:57:09 发布

原创最新推荐文章于 2022-05-15 08:57:09 发布 · 455 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#function #algorithm #numbers

本文介绍了一种在数组中找到出现次数为奇数次的数字的方法。通过使用位运算中的异或操作，可以在O(n)的时间复杂度内完成任务，并且只需要常数级别的额外空间。文章还提供了一个C语言实现的例子。

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.

Example:
I/P = [1, 2, 3, 2, 3, 1, 3]
O/P = 3

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

Program:

#include <stdio.h> 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; } /* Diver function to test above function */ int main() { int ar[] = {2, 3, 5, 4, 5, 2, 4, 3, 5, 2, 4, 4, 2}; printf("%d", getOddOccurrence(ar, 13)); getchar(); }