比如: 15 0000 1111 4 个 1
程序原型:
int count_one_bits(unsigned int value)
{
// 返回 1的位数
}
第一种方法:(不能处理负数)
int main()//不能处理负数
{
int num = 15;
int count = 0;
while (num)
{
count++;
num /= 2;
}
printf("%d\n", count);
system("pause");
return 0;
}
按位与的方法:
int main()//按位与
{
int num = -1;
int count = 0;
int i = 0;
for (i = 0; i < 32; i++)
{
if ((num >> 1) & 1 == 1)
{
count++;
}
}
printf("%d\n", count);
system("pause");
return 0;
}
int main()
{
int num = -1;
int count = 0;
while (num)
{
num = num&(num - 1);
count++;
}
printf("%d\n", count);
system("pause");
return 0;
}
无符号的处理;
int count_one_bit(unsigned int n)//无符号数
{
int count = 0;
while (n)
{
if (n % 2 == 1)
count++;
n = n / 2;
}
return count;
}
int main()
{
int num = -1;
int ret = count_one_bit(num);
printf("%d\n", ret);
system("pause");
}