在一行中生成大小为 2 到全 0 的给定二进制数组

给定一个二进制数组arr[N] ，（其中N = 2 ）大小为 2，至少有一个元素为零。任务是编写一个单行函数来将数组的两个元素都设置为零。编写函数有一个限制。不能使用三元运算符和元素的直接赋值。

As per problem constraints, only three combinations of array elements are possible:

1. arr[0] = 1 and arr[1] = 0
2. arr[0] = 0 and arr[1] = 1
3. arr[0] = 0 and arr[1] = 0

本文讨论了以下方法：

1. 仅使用赋值运算符。
2. 使用赋值运算符两次。
3. 否定 (!)运算符（逻辑非）。

让我们开始详细讨论这些方法。

1.仅使用赋值运算符：

赋值运算符可用于将给定二进制数组的两个元素都设置为 0，但在这种方法中，不直接使用索引。

方法：

有三种方法可以实现这一点：

1. arr[arr[1]] = arr[arr[0]]
If arr={0, 1}, then arr[0] will be assigned to arr[1].
If arr={1, 0}, then arr[1] will be assigned to arr[0].

2. arr[arr[1]] = 0
If arr[1]=0, then arr[0] will be 1, so arr[arr[1]] will make arr[0]=0.
If arr[1]=1, then arr[1] will be 1, so arr[arr[1]] will make arr[1]=0.

3. arr[1 – arr[0]] = arr[1 – arr[1]]
If arr[1]=0 and arr[0]=1, then 1-arr[1] will be 1, so arr[1] will be assigned to arr[0].
If arr[1]=1 and arr[0]=0, then 1-arr[1] will be 0, so arr[0] will be assigned to arr[1].

下面是实现该方法的 C++ 代码：

C++

// C++ program to set both elements
// to 0 in binary array[2].
#include 
using namespace std;
 
void MakeBothZeros(int arr[])
{
    arr[arr[1]] = arr[arr[0]];
 
    // Two other approaches to solve
    // the problem
    // arr[arr[1]] = 0;
    // arr[1 - arr[0]] = arr[1 - arr[1]];
}
 
// Driver code
int main()
{
    int First_Arr[] = {0, 1};
    MakeBothZeros(First_Arr);
    cout << First_Arr[0] << " " <<
            First_Arr[1] << endl;
 
    int Second_Arr[] = {1, 0};
    MakeBothZeros(Second_Arr);
    cout << Second_Arr[0] << " " <<
            Second_Arr[1] << endl;
 
    int Thrd_Arr[] = {0, 0};
    MakeBothZeros(Thrd_Arr);
    cout << Thrd_Arr[0] << " " <<
            Thrd_Arr[1] << endl;
 
    return 0;
}

Java

// Java program to set both elements
// to 0 in binary array[2]
import java.util.*;
class GFG{
 
static void MakeBothZeros(int arr[])
{
    arr[arr[1]] = arr[arr[0]];
 
    // Two other approaches to solve
    // the problem
    // arr[arr[1]] = 0;
    // arr[1 - arr[0]] = arr[1 - arr[1]];
}
 
// Driver code
public static void main(String[] args)
{
    int First_Arr[] = {0, 1};
    MakeBothZeros(First_Arr);
    System.out.print(First_Arr[0]+ " " + 
            First_Arr[1] +"\n");
 
    int Second_Arr[] = {1, 0};
    MakeBothZeros(Second_Arr);
    System.out.print(Second_Arr[0]+ " " + 
            Second_Arr[1] +"\n");
 
    int Thrd_Arr[] = {0, 0};
    MakeBothZeros(Thrd_Arr);
    System.out.print(Thrd_Arr[0]+ " " + 
            Thrd_Arr[1] +"\n");
 
}
}
 
// This code is contributed by 29AjayKumar

Python3

# Python code for the above approach
def MakeBothZeros(arr):
    arr[arr[1]] = arr[arr[0]]
 
    # Two other approaches to solve
    # the problem
    # arr[arr[1]] = 0;
    # arr[1 - arr[0]] = arr[1 - arr[1]];
 
# Driver code
First_Arr = [0, 1]
MakeBothZeros(First_Arr)
print(f"{First_Arr[0]} {First_Arr[1]}  ")
 
Second_Arr = [1, 0]
MakeBothZeros(Second_Arr)
print(f"{Second_Arr[0]} {Second_Arr[1]} ")
 
Thrd_Arr = [0, 0]
MakeBothZeros(Thrd_Arr)
print(f"{Thrd_Arr[0]} {Thrd_Arr[1]} ")
 
# This code is contributed by GFGKING

C#

// C# program to set both elements
// to 0 in binary array[2]
using System;
class GFG {
 
  static void MakeBothZeros(int[] arr)
  {
    arr[arr[1]] = arr[arr[0]];
 
    // Two other approaches to solve
    // the problem
    // arr[arr[1]] = 0;
    // arr[1 - arr[0]] = arr[1 - arr[1]];
  }
 
  // Driver code
  public static void Main()
  {
    int[] First_Arr = { 0, 1 };
    MakeBothZeros(First_Arr);
    Console.WriteLine(First_Arr[0] + " "
                      + First_Arr[1]);
 
    int[] Second_Arr = { 1, 0 };
    MakeBothZeros(Second_Arr);
    Console.WriteLine(Second_Arr[0] + " "
                      + Second_Arr[1]);
 
    int[] Thrd_Arr = { 0, 0 };
    MakeBothZeros(Thrd_Arr);
    Console.WriteLine(Thrd_Arr[0] + " " + Thrd_Arr[1]);
  }
}
 
// This code is contributed by ukasp.

Javascript

      // JavaScript code for the above approach
 
      function MakeBothZeros(arr) {
          arr[arr[1]] = arr[arr[0]];
 
          // Two other approaches to solve
          // the problem
          // arr[arr[1]] = 0;
          // arr[1 - arr[0]] = arr[1 - arr[1]];
      }
 
      // Driver code
 
      let First_Arr = [0, 1];
      MakeBothZeros(First_Arr);
      document.write(First_Arr[0] + " " +
          First_Arr[1] + "<br>");
 
      let Second_Arr = [1, 0];
      MakeBothZeros(Second_Arr);
      document.write(Second_Arr[0] + " " +
          Second_Arr[1] + '<br>');
 
      let Thrd_Arr = [0, 0];
      MakeBothZeros(Thrd_Arr);
      document.write(Thrd_Arr[0] + " " +
          Thrd_Arr[1] + '<br>');
 
// This code is contributed by Potta Lokesh
  

输出

0 0
0 0
0 0

2. 使用赋值运算符两次：

如约束中所列，不允许直接分配。因此 arr[0]=0 和 arr[1]=0 不是有效的语句。赋值运算符将被使用两次以将两个元素都设置为零。

方法：

有三种方法可以实现这一点：

1. arr[0] = arr[1] = arr[0] & arr[1]
if any one of the elements is 1. 
AND of 1 and 0 is always 0. So, both gets value 0.

2. arr[0] = arr[1] -= arr[1]
If arr[1]=1 then arr[1] gets 1-1=0 so, both becomes 0.

3. arr[1] = arr[0] -= arr[0]
If arr[0]=1, then arr[0] gets 1-1=0.
else arr[0]= 0-0 = 0. So, both becomes 0.

下面是实现该方法的 C++ 程序：

C++

// C++ program to set both elements
// to 0 in binary array[2].
#include 
using namespace std;
 
void MakeBothZeros(int arr[])
{
    arr[0] = arr[1] = arr[0] & arr[1];
 
    // Two other approaches to solve
    // the problem
    // arr[0] = arr[1] -= arr[1];
    // arr[1] = arr[0] -= arr[0];
}
 
// Driver code
int main()
{
    int First_Arr[] = {0, 1};
    MakeBothZeros(First_Arr);
    cout << First_Arr[0] << " " <<
            First_Arr[1] << endl;
 
    int Second_Arr[] = {1, 0};
    MakeBothZeros(Second_Arr);
    cout << Second_Arr[0] << " " <<
            Second_Arr[1] << endl;
 
    int Thrd_Arr[] = {0, 0};
    MakeBothZeros(Thrd_Arr);
    cout << Thrd_Arr[0] << " " <<
            Thrd_Arr[1] << endl;
 
    return 0;
}

Java

// Java program to set both elements
// to 0 in binary array[2].
 
import java.util.*;
 
class GFG{
 
static void MakeBothZeros(int arr[])
{
    arr[0] = arr[1] = arr[0] & arr[1];
 
    // Two other approaches to solve
    // the problem
    // arr[0] = arr[1] -= arr[1];
    // arr[1] = arr[0] -= arr[0];
}
 
// Driver code
public static void main(String[] args)
{
    int First_Arr[] = {0, 1};
    MakeBothZeros(First_Arr);
    System.out.print(First_Arr[0]+ " " + 
            First_Arr[1] +"\n");
 
    int Second_Arr[] = {1, 0};
    MakeBothZeros(Second_Arr);
    System.out.print(Second_Arr[0]+ " " + 
            Second_Arr[1] +"\n");
 
    int Thrd_Arr[] = {0, 0};
    MakeBothZeros(Thrd_Arr);
    System.out.print(Thrd_Arr[0]+ " " + 
            Thrd_Arr[1] +"\n");
 
}
}
 
// This code is contributed by 29AjayKumar

Python3

# Python program to set both elements
# to 0 in binary array[2].
def MakeBothZeros(arr):
 
    arr[0] = arr[1] = arr[0] & arr[1]
 
    # Two other approaches to solve
    # the problem
    # arr[0] = arr[1] -= arr[1];
    # arr[1] = arr[0] -= arr[0];
 
# Driver code
First_Arr = [0, 1]
MakeBothZeros(First_Arr)
print(First_Arr[0], end=" ")
print(First_Arr[1])
 
Second_Arr = [0, 1]
MakeBothZeros(Second_Arr)
print(Second_Arr[0], end=" ")
print(Second_Arr[1])
 
 
Thrd_Arr = [0, 0]
MakeBothZeros(Thrd_Arr)
print(Thrd_Arr[0], end=" ")
print(Thrd_Arr[1])
 
# This code is contributed by Samim Hossain Mondal.

C＃

// C# program to set both elements
// to 0 in binary array[2].
using System;
public class GFG
{
 
  static void MakeBothZeros(int []arr)
  {
    arr[0] = arr[1] = arr[0] & arr[1];
 
    // Two other approaches to solve
    // the problem
    // arr[0] = arr[1] -= arr[1];
    // arr[1] = arr[0] -= arr[0];
  }
 
  // Driver code
  public static void Main(String[] args) {
    int[] First_Arr = { 0, 1 };
    MakeBothZeros(First_Arr);
    Console.Write(First_Arr[0] + " " + First_Arr[1] + "\n");
 
    int []Second_Arr = { 1, 0 };
    MakeBothZeros(Second_Arr);
    Console.Write(Second_Arr[0] + " " + Second_Arr[1] + "\n");
 
    int []Thrd_Arr = { 0, 0 };
    MakeBothZeros(Thrd_Arr);
    Console.Write(Thrd_Arr[0] + " " + Thrd_Arr[1] + "\n");
 
  }
}
 
// This code is contributed by Rajput-Ji

Javascript

// Javascript program to set both elements
// to 0 in binary array[2].
 
function MakeBothZeros(arr) {
 
    arr[0] = arr[1] = arr[0] & arr[1]
 
    // Two other approaches to solve
    // the problem
    // arr[0] = arr[1] -= arr[1];
    // arr[1] = arr[0] -= arr[0];
}
 
// Driver code
let First_Arr = [0, 1];
MakeBothZeros(First_Arr);
document.write(First_Arr[0] + " " +
            First_Arr[1]);
 
let Second_Arr = [1, 0];
MakeBothZeros(Second_Arr);
document.write(Second_Arr[0] + " " +
            Second_Arr[1]);
 
let Thrd_Arr = [0, 0];
MakeBothZeros(Thrd_Arr);
document.write(Thrd_Arr[0] + " " +
            Thrd_Arr[1]);
             
// This code is contributed by Samim Hossain Mondal.

输出

0 0
0 0
0 0

笔记：
时间复杂度为 O(1)，因为只使用了一条语句。

3. 通过使用否定 (!)运算符（逻辑非）：

在这种方法中，赋值运算符与否定运算符一起使用，在一行代码中使给定数组的两个元素都为 0。

方法：

有三种方法可以做到这一点：

1. arr[!arr[0]] = arr[arr[0]]
If arr={0, 1} then index 1 is assigned the index 0 value.
If arr={1, 0} then index 0 is given the index 1 value.

2. arr[arr[1]] = arr[!arr[1]]
If arr={0, 1} then index 0 value is assigned to the index 1.
If arr={1, 0} then index 1 value is assigned to the index 0.

3. arr[!arr[0]] = arr[!arr[1]]
If arr={0, 1}, since 1 is the value at index 1, the index 0 value which is 0 again,  
will be assigned to index 1, making array full of zeros.
If arr={1, 0} then index 1 value is assigned to the index 0.

下面是实现该方法的 C++ 程序：

C++

// C++ program to set both elements
// to 0 in binary array[2].
#include 
using namespace std;
 
void MakeBothZeros(int arr[])
{
    arr[!arr[0]] = arr[arr[0]];
 
    // Two other approaches to solve
    // the problem
    // arr[arr[1]] = arr[!arr[1]]
    // arr[!arr[0]] = arr[!arr[1]]
}
 
// Driver code
int main()
{
    int First_Arr[] = {0, 1};
    MakeBothZeros(First_Arr);
    cout << First_Arr[0] << " " <<
            First_Arr[1] << endl;
 
    int Second_Arr[] = {1, 0};
    MakeBothZeros(Second_Arr);
    cout << Second_Arr[0] << " " <<
            Second_Arr[1] << endl;
 
    int Thrd_Arr[] = {0, 0};
    MakeBothZeros(Thrd_Arr);
    cout << Thrd_Arr[0] << " " <<
            Thrd_Arr[1] << endl;
 
    return 0;
}

Javascript

 
// JavaScript program to set both elements
// to 0 in binary array[2].
function MakeBothZeros(arr)
{
    arr[Number(!arr[0])] = arr[arr[0]];
 
    // Two other approaches to solve
    // the problem
    // arr[arr[1]] = arr[!arr[1]]
    // arr[!arr[0]] = arr[!arr[1]]
}
 
// Driver code
let First_Arr = [0, 1];
MakeBothZeros(First_Arr);
document.write(First_Arr[0] + " " + First_Arr[1],"</br>");
 
let Second_Arr = [1, 0];
MakeBothZeros(Second_Arr);
document.write(Second_Arr[0] + " " + Second_Arr[1],"</br>")
 
let Third_Arr = [0, 0];
MakeBothZeros(Third_Arr);
document.write(Third_Arr[0] + " " + Third_Arr[1],"</br>")
 
// This code is contributed by shinjanpatra
 

输出

0 0
0 0
0 0