原文連結：Bitwise Operation Explained
1.統計一個數置位為1的個數
複制代碼
#include <stdio.h>
int __numOf_SET_Bits(int var)
{
if (var==0) return 0;
else return (var&01)?1+__numOf_SET_Bits(var>>1):__numOf_SET_Bits(var>>1);
}
int main()
int var=128;
printf("Num of Bits: %d\n",__numOf_SET_Bits(var));
return 0;
2,判斷一個數是奇數還是偶數
#define isEven(a) ((((a)&01)==0)?1:0)
int var=1;
if(isEven(var))
{
printf("%d is a even number \n",var);
}
else
printf("%d is a odd number \n",var);
方法二：
#define isEven(a) ((((a)%2)==0)?1:0)
int var=11;
3，判斷一個數是否是2的幂次方
#define __isPower_of_TWO(a) (((a)&(a-1))==0)?1:0
int arr[] = {1,2,3,4,5,8,9,16};
int i=0;
for(;i<sizeof(arr)/sizeof(arr[0]);i++)
if (__isPower_of_TWO(*(arr+i)))
printf("%d has a form of Power of Two \n",*(arr+i));
else
printf("%d is not in the form \n", *(arr+i));
#define __isPower_of_TWO(a) (((a)&(-a))==a)?1:0
方法三：
複制代碼
#include <stdlib.h>
if (__numOf_SET_Bits(arr[i])==1)
system("pause");
4，不使用第三個數，交換兩個數
void __SWAP(int *a,int *b)
*a = *a ^ *b;
*b = *a ^ *b;
int a=5, b=6;
printf("Before swap: a=%d <=====> b=%d \n",a,b);
__SWAP(&a,&b);
printf("After swap: a=%d <=====> b=%d \n",a,b);
5，異或雙向連結清單
#include <assert.h>
typedef struct XOR_based_Node
int data;//資料域
unsigned long compressedAddress;
}node;
node* head = NULL;//異或雙向連結清單表頭
void add_element_to_list(node** headRef, int data)
{//插入表頭
node *newNode = (node*)malloc(sizeof(node));
assert(newNode);
newNode->compressedAddress = (unsigned long)(*headRef);
newNode->data = data;
if(*headRef != NULL)
(*headRef)->compressedAddress ^= (unsigned long)newNode;
*headRef=newNode;
void printList(node* head)
{//輸出表
unsigned long prev = 0;
while(head)
unsigned long next = prev ^ head->compressedAddress;
printf("%d ", head->data);
prev = (unsigned long)head;
head = (node *)next;
printf("\n");
int main(void)
for(;i<10;i++)
add_element_to_list(&head,i);
printList(head);
本文轉自Phinecos(洞庭散人)部落格園部落格，原文連結：http://www.cnblogs.com/phinecos/archive/2008/08/22/1273784.html，如需轉載請自行聯系原作者