获得一个int数中二进制位为1 的个数

 

int 

NumberOfOne(

int 

n

){

                 

int 

count = 0;

                 

unsigned 

int 

flag = 1;

                 

while 

(flag){

                                 

if 

(

n 

& flag){

                                                count++;

                                }

                                flag = flag << 1;

                }

                 

return 

count;

}

int 

NumberOfOne2(

int 

n

){

                 

int 

count = 0;

                 

while 

(

n 

)

                {

                                count++;

                                 

n 

= 

n 

&(

n 

- 1);

                }

                 

return 

count;

}