给定一个数组A和两个整数M和K ,任务是检查并打印“ Yes ”,如果可以通过对数组元素与“ M ”执行精确的“ K ”个按位XOR运算来保留原始数组。否则打印“否”。
注意:可以在数组的任何元素上执行0次或多次XOR操作。
例子:
Input: A[] = {1, 2, 3, 4}, M = 5, K = 6
Output: Yes
Explanation:
If the XOR is performed on 1st element, A[0], for 6 times, we get A[0] back. Therefore, the original array is retained.
Input: A[] = {5, 9, 3, 4, 5}, M = 5, K = 3
Output: No
Explanation:
The original array cant be retained after performing odd number of XOR operations.
方法:可以使用XOR属性解决此问题
A XOR B = C and C XOR B = A
可以看出:
- 如果对任何正数执行偶数个XOR操作,则可以保留原始数。
- 但是,0是一个例外。如果对0进行了奇数或偶数的XOR运算,则可以保留原始数。
- 因此,如果K为偶数且M为0 ,则答案将始终为是。
- 如果K为奇数且数组中不存在0 ,则答案将始终为否。
- 如果K为奇数,并且数组中的0至少为1 ,则答案为是。
下面是上述方法的实现:
C++
// C++ implementation for the
// above mentioned problem
#include
using namespace std;
// Function to check if original Array
// can be retained by performing XOR
// with M exactly K times
string check(int Arr[], int n,
int M, int K)
{
int flag = 0;
// Check if O is present or not
for (int i = 0; i < n; i++) {
if (Arr[i] == 0)
flag = 1;
}
// If K is odd and 0 is not present
// then the answer will always be No.
if (K % 2 != 0
&& flag == 0)
return "No";
// Else it will be Yes
else
return "Yes";
}
// Driver Code
int main()
{
int Arr[] = { 1, 1, 2, 4, 7, 8 };
int M = 5;
int K = 6;
int n = sizeof(Arr) / sizeof(Arr[0]);
cout << check(Arr, n, M, K);
return 0;
}
Java
import java.util.*;
class GFG{
// Function to check if original Array
// can be retained by performing XOR
// with M exactly K times
static String check(int []Arr, int n,
int M, int K)
{
int flag = 0;
// Check if O is present or not
for (int i = 0; i < n; i++) {
if (Arr[i] == 0)
flag = 1;
}
// If K is odd and 0 is not present
// then the answer will always be No.
if (K % 2 != 0
&& flag == 0)
return "No";
// Else it will be Yes
else
return "Yes";
}
// Driver Code
public static void main(String args[])
{
int []Arr = { 1, 1, 2, 4, 7, 8 };
int M = 5;
int K = 6;
int n = Arr.length;
System.out.println(check(Arr, n, M, K));
}
}
// This code is contributed by Surendra_Gangwar
Python3
# Python3 implementation for the
# above mentioned problem
# Function to check if original Array
# can be retained by performing XOR
# with M exactly K times
def check(Arr, n, M, K):
flag = 0
# Check if O is present or not
for i in range(n):
if (Arr[i] == 0):
flag = 1
# If K is odd and 0 is not present
# then the answer will always be No.
if (K % 2 != 0 and flag == 0):
return "No"
# Else it will be Yes
else:
return "Yes";
# Driver Code
if __name__=='__main__':
Arr = [ 1, 1, 2, 4, 7, 8 ]
M = 5;
K = 6;
n = len(Arr);
print(check(Arr, n, M, K))
# This article contributed by Princi Singh
C#
// C# implementation for the
// above mentioned problem
using System;
class GFG
{
// Function to check if original Array
// can be retained by performing XOR
// with M exactly K times
static String check(int []Arr, int n,int M, int K)
{
int flag = 0;
// Check if O is present or not
for (int i = 0; i < n; i++) {
if (Arr[i] == 0)
flag = 1;
}
// If K is odd and 0 is not present
// then the answer will always be No.
if (K % 2 != 0
&& flag == 0)
return "No";
// Else it will be Yes
else
return "Yes";
}
// Driver code
public static void Main(String[] args)
{
int []Arr = { 1, 1, 2, 4, 7, 8 };
int M = 5;
int K = 6;
int n = Arr.Length;
Console.Write(check(Arr, n, M, K));
}
}
// This code is contributed by shivanisinghss2110
输出:
Yes