Number of binaries (JAVA)

Number of 1 in binary
　　

Title Description Enter an integer that outputs the number of 1 in the binary representation.　　　　　　　　Where negative numbers are expressed in complement. Idea: Use bitwise arithmetic to move 1 operations.　　　　　　(First you have to know that the number in the computer is placed in 01来) 1, if by a number 11100, when its minus 1 is 11011, that is, minus 1 will be the number of the rightmost 1 to 0, and all subsequent numbers are reversed. 2, the two number and the 11000, the rightmost 1 becomes 0, and the other number is unchanged.　　　　　　At this point 1 numbers plus 1.　　　　　　　　　　　　3, repeat the operation until the number becomes 0, and get the number of all 1. The code is simple, as follows.

1      Public int NUMBEROF1 (int  n) {2         int count = 0; 3          while (n!=0) {4             count++; 5             n = n& (n-1); 6         }7         return  count; 8     }

Number of binaries (JAVA)