C# Program for Count set bits in an integer
Write an efficient program to count number of 1s in binary representation of an integer.
Examples :
Input : n = 6 Output : 2 Binary representation of 6 is 110 and has 2 set bits Input : n = 13 Output : 3 Binary representation of 11 is 1101 and has 3 set bits
Recommended: Please solve it on “PRACTICE ” first, before moving on to the solution.
1. Simple Method Loop through all bits in an integer, check if a bit is set and if it is then increment the set bit count. See below program.
C#
// C# program to Count set// bits in an integerusing System; class GFG { // Function to get no of set // bits in binary representation // of positive integer n static int countSetBits(int n) { int count = 0; while (n > 0) { count += n & 1; n >>= 1; } return count; } // Driver Code public static void Main() { int i = 9; Console.Write(countSetBits(i)); }} // This code is contributed by Sam007 |
Output:
2
Recursive Approach :
C#
// C# implementation of recursive// approach to find the number of// set bits in binary representation// of positive integer nusing System; class GFG { // recursive function // to count set bits public static int countSetBits(int n) { // base case if (n == 0) return 0; else // if last bit set // add 1 else add 0 return (n & 1) + countSetBits(n >> 1); } // Driver code static public void Main() { // get value // from user int n = 9; // function calling Console.WriteLine(countSetBits(n)); }} // This code is contributed by aj_36 |
Output:
2
Please refer complete article on Count set bits in an integer for more details!
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