Given an integer n, find the one’s complement of the integer.
Examples:
Input : n = 5 Output : 2 Input : n = 255 Output : 0 Input : n = 26 Output : 5
An efficient approach to this problem is as follows:
1. Find the number of bits in the given integer
2. XOR the given integer with 2^number_of_bits-1
C++
// CPP program to find 1's complement of n. #include<bits/stdc++.h> using namespace std; unsigned int onesComplement(unsigned int n) { // Find number of bits in the given integer int number_of_bits = floor(log2(n))+1; // XOR the given integer with poe(2, // number_of_bits-1 and print the result return ((1 << number_of_bits) - 1) ^ n; } int main() { unsigned int n = 22; cout << onesComplement(n); return 0; } |
Java
// Java program to find 1's complement of n. class GFG { static int onesComplement(int n) { // Find number of bits in the // given integer int number_of_bits = (int)(Math.floor(Math.log(n) / Math.log(2))) + 1; // XOR the given integer with poe(2, // number_of_bits-1 and print the result return ((1 << number_of_bits) - 1) ^ n; } // Driver code public static void main(String[] args) { int n = 22; System.out.print(onesComplement(n)); } } // This code is contributed by Anant Agarwal. |
Python3
# Python3 program to find # 1's complement of n. import math def onesComplement(n): # Find number of bits in # the given integer number_of_bits = (int)(math.floor(math.log(n) / math.log(2))) + 1; # XOR the given integer with poe(2, # number_of_bits-1 and print the result return ((1 << number_of_bits) - 1) ^ n; # Driver code n = 22print(onesComplement(n)) # This code is contributed by Anant Agarwal. |
C#
// C# program to find 1's complement of n. using System; class GFG { static int onesComplement(int n) { // Find number of bits in the given integer int number_of_bits = (int)(Math.Floor( Math.Log(n) / Math.Log(2))) + 1; // XOR the given integer with poe(2, // number_of_bits-1 and print the result return ((1 << number_of_bits) - 1) ^ n; } //Driver code public static void Main () { int n = 22; Console.WriteLine(onesComplement(n)); } } // This code is contributed by Anant Agarwal. |
PHP
<?php // PHP program to find 1's // complement of n. function Log2($x) { return (log10($x) / log10(2)); } function onesComplement($n) { // Find number of bits in // the given integer $number_of_bits = floor(log2($n)) + 1; // XOR the given integer with // number_of_bits-1 and print the result return ((1 << $number_of_bits) - 1) ^ $n; } // Driver Code $n = 22; echo onesComplement($n); // This code is contributed by ihritik ?> |
Output :
9
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