Set all odd bits of a number | Efficient Java program to set all odd bits number ; return MSB set number ; set all bits including MSB . ; return MSB ; Returns a number of same size ( MSB at same position ) as n and all odd bits set . ; generate odd bits like 010101. . ; if bits is even then shift by 1 ; return odd set bits number ; set all odd bits here ; take OR with odd set bits number ; Driver code
class GFG { static int getmsb ( int n ) { n |= n >> 1 ; n |= n >> 2 ; n |= n >> 4 ; n |= n >> 8 ; n |= n >> 16 ; return ( n + 1 ) >> 1 ; } static int getevenbits ( int n ) { n = getmsb ( n ) ; n |= n >> 2 ; n |= n >> 4 ; n |= n >> 8 ; n |= n >> 16 ; if ( ( n & 1 ) == 0 ) n = n >> 1 ; return n ; } static int setalloddbits ( int n ) { return n | getevenbits ( n ) ; } public static void main ( String [ ] args ) { int n = 10 ; System . out . println ( setalloddbits ( n ) ) ; } }