给定一个整数 。任务是查找在给定数字加1后更改的位数。
例子:
Input : N = 5
Output : 2
After adding 1 to 5 it becomes 6.
Binary representation of 5 is 101.
Binary representation of 6 is 110.
So, no. of bits changed is 2.
Input : N = 1
Output : 2
有三种方法可以找到将给定值N加1后获得的结果中的更改位数:
- 方法1:将1与给定的整数相加,比较N的位数和相加后得到的结果,并对不匹配位数进行计数。
- 方法2:如果将1加到N,则更改的总位数由从右起第1个零的位置(即LSB为零)定义。在这种情况下,将1加1,然后对其进行更改,并将进位1传递到其下一位;但是,如果将1加到0,则只有0变为1,并且不再传递进位。
- 方法3:要查找将给定数字加1时已更改的位数,请对n和n + 1进行XOR,然后计算所得XOR值中的置位位数。
以下是方法3的实现:
C++
// CPP program to find the number
// of changed bit
#include
using namespace std;
// Function to find number of changed bit
int findChangedBit(int n)
{
// Calculate xor of n and n+1
int XOR = n ^ (n + 1);
// Count set bits in xor value
int result = __builtin_popcount(XOR);
// Return the result
return result;
}
// Driver function
int main()
{
int n = 6;
cout << findChangedBit(n) << endl;
n = 7;
cout << findChangedBit(n);
return 0;
}
Java
// Java program to find the number
// of changed bit
class GFG
{
// Function to find number of changed bit
static int findChangedBit(int n)
{
// Calculate xor of n and n+1
int XOR = n ^ (n + 1);
// Count set bits in xor value
int result = Integer.bitCount(XOR);
// Return the result
return result;
}
// Driver code
public static void main(String[] args)
{
int n = 6;
System.out.println(findChangedBit(n));
n = 7;
System.out.println(findChangedBit(n));
}
}
// This code contributed by Rajput-Ji
Python3
# Python 3 program to find the number
# of changed bit
# Function to find number of changed bit
def findChangedBit(n):
# Calculate xor of n and n+1
XOR = n ^ (n + 1)
# Count set bits in xor value
result = bin(XOR).count("1")
# Return the result
return result
# Driver Code
if __name__ == '__main__':
n = 6
print(findChangedBit(n))
n = 7
print(findChangedBit(n))
# This code is contributed by
# Surendra_Gangwar
C#
// C# program to find the number
// of changed bit
using System;
class GFG
{
// Function to find number of changed bit
static int findChangedBit(int n)
{
// Calculate xor of n and n+1
int XOR = n ^ (n + 1);
// Count set bits in xor value
int result = bitCount(XOR);
// Return the result
return result;
}
static int bitCount(int x)
{
// To store the count
// of set bits
int setBits = 0;
while (x != 0)
{
x = x & (x - 1);
setBits++;
}
return setBits;
}
// Driver code
public static void Main(String[] args)
{
int n = 6;
Console.WriteLine(findChangedBit(n));
n = 7;
Console.WriteLine(findChangedBit(n));
}
}
/* This code contributed by PrinciRaj1992 */
输出:
1
4