回调函数
有点类似模板的功能,可以使用函数指针作为参数,当调用函数时,使用void *进行传递参数,细致比较时,再用int *之类的进行强制转换。回调函数,其实就是在参数中定义函数,调用时,回到主函数去调用这个函数。仔细用法如下:
首先定义查找函数
Node * search_list(Node *node, void const *value, int (*compare)(void const *,void const *)){ while(node!=NULL){ if(compare(&node->data,value) == 0 ) break; node = node->next; } return node; }
比较函数
int compare_ints(void const *a,void const *b){ if( *(int *)a == *(int *)b) return 0; else return 1; }
函数中的调用
int *desire = (int *)malloc(sizeof(int)); *desire = 3; Node *n1 = (Node *)malloc(sizeof(Node)); n1 = search_list(L->next,desire,compare_ints); if(n1!=NULL) printf("找到了%d",n1->data);
全部代码
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 #include <stdio.h> 2 #include <stdlib.h> 3 4 typedef struct Node{ 5 int data; 6 struct Node * next; 7 }Node; 8 9 void createList(Node * L,int len); 10 void showList(Node *L); 11 void clearList(Node *L); 12 void getNode(Node *L,int n,Node *tar); 13 int insertNode(Node *L,int n,int num); 14 int deleteNode(Node *L,int n); 15 Node * search_list(Node *node, void const *value, int (*compare)(void const *,void const *)); 16 int compare_ints(void const *a,void const *b); 17 18 int main() 19 { 20 Node *L= (Node *)malloc(sizeof(Node)); 21 22 createList(L,5); 23 showList(L); 24 25 Node *tar= (Node *)malloc(sizeof(Node)); 26 getNode(L,3,tar); 27 printf("the third is:%d\n",tar->data); 28 29 if(insertNode(L,3,0)) 30 showList(L); 31 32 printf("回调函数:\n"); 33 int *desire = (int *)malloc(sizeof(int)); 34 *desire = 3; 35 Node *n1 = (Node *)malloc(sizeof(Node)); 36 n1 = search_list(L->next,desire,compare_ints); 37 if(n1!=NULL) 38 printf("找到了%d",n1->data); 39 40 /* 41 if(deleteNode(L,3)) 42 showList(L); 43 44 clearList(L); 45 showList(L); 46 */ 47 48 /**desire = 9; 49 Node *n2 = search_list(L,desire,compare_ints); 50 if(n2!=NULL) 51 printf("找到了%d",n2->data); 52 *desire = 7; 53 Node *n3 = search_list(L,desire,compare_ints); 54 if(n3!=NULL) 55 printf("找到了%d",n3->data);*/ 56 getchar(); 57 return 0; 58 } 59 Node * search_list(Node *node, void const *value, int (*compare)(void const *,void const *)){ 60 while(node!=NULL){ 61 if(compare(&node->data,value) == 0 ) 62 break; 63 node = node->next; 64 } 65 return node; 66 } 67 int compare_ints(void const *a,void const *b){ 68 if( *(int *)a == *(int *)b) 69 return 0; 70 else 71 return 1; 72 } 73 74 void createList(Node * L,int len){ 75 int i; 76 Node * p; 77 L->next = NULL; 78 for(i=0;i<len;i++){ 79 p = (Node *)malloc(sizeof(Node)); 80 p->data = 2*i+1; 81 p->next = L->next; 82 L->next = p; 83 } 84 } 85 86 void showList(Node *L){ 87 Node *p = (Node *)malloc(sizeof(Node)); 88 p=L->next; 89 while(p){ 90 printf("%d->",p->data); 91 p=p->next; 92 } 93 printf("null\n"); 94 free(p); 95 } 96 97 void clearList(Node *L){ 98 Node *p,*q; 99 p=L->next; 100 while(p){ 101 q=p->next; 102 free(p); 103 p=q; 104 } 105 L->next=NULL; 106 } 107 108 void getNode(Node *L,int n,Node *tar){ 109 int i=1; 110 Node *p; 111 p=L->next; 112 while(p && i<n){ 113 p=p->next; 114 i++; 115 } 116 if(!p || i>n) 117 printf("error!"); 118 tar->data=p->data; 119 } 120 121 int insertNode(Node *L,int n,int num){ 122 int i=1; 123 Node *p = L->next; 124 while( p && i<n-1){ 125 p=p->next; 126 i++; 127 } 128 if(!p || i>n-1) 129 return 0; 130 Node *q = (Node *)malloc(sizeof(Node)); 131 q->data = num; 132 q->next = p->next; 133 p->next = q; 134 return 1; 135 } 136 137 int deleteNode(Node *L,int n){ 138 int i=1; 139 Node *p = L->next; 140 Node *q; 141 while( p->next && i<n-1){ 142 p=p->next; 143 i++; 144 } 145 if( !(p->next) || i>n-1) 146 return 0; 147 q=p->next; 148 p->next = q->next; 149 free(q); 150 return 1; 151 }