[数据结构与算法]C++ 异或运算求数组中重复的一个数

#include<iostream>
#include<stdlib.h>
using namespace std;
void establishData(int a[],int length)
{
	srand((int)time(NULL));
	
	//随机产生10个数(randomly generate 10 number)
	for (int i = 0; i < length - 1; ++i)
	{
		a[i] = rand() % 10 + 1;//产生1到10的数（produces a number from 1 to 10)
		for (int j = 0; j < i; ++j)
		{
			if (a[j] == a[i])//排除重复的数
			{
				--i;
			}
		}
	}
	//在最后一个位置放入一个重复数(put a repeat number in the last number)
	a[length - 1] = rand() % 10 + 1;
	//将该位随机与一个不相等的数交换位置(randomly swap this bit with an unequal number)
	int index = rand() % 10 + 1;
	while (a[index] == a[length - 1])
	{
		index = rand() % 10 + 1;
	}
	int temp = a[index];
	a[index] = a[length - 1];
	a[length - 1] = temp;
}
int main()
{
	int a[11];
	int length = sizeof(a) / sizeof(a[0]);
	establishData(a,length);
	cout << "a数组11个数据" << endl;
	for (int i = 0; i < length; ++i)
	{
		cout << a[i] << " ";
	}
	cout << endl;

	//用^(异或)运算，0与任何数做异或运算都为该数本身
	//with the^(exclusive or)operation,the exclusive or operation between 0 and any number is the number itself)
	int result=0;
	int i = 0;
	for (int i = 1; i <= length - 1; ++i)
	{
		result ^= i;
	}
	
	for (; i < length; ++i)
	{
		
		result ^= a[i];
		
		
		if (result == 0)
		{
			break;
		}
	}


	cout << endl << endl;
	cout << "结果得" << " ";
	cout << a[i]<<" 重复";
}