C和指针中文版PDF

C和指针:字符串的查找、删除、反向排列(2008-12-28 16:37:00)转载▼标签：c语言指针数据结构与算法it#include<stdio.h>#include<conio.h>#include<string.h>#include<stdlib.h>int find_string(const char *source ,const char *chars) {if(source==NULL || chars==NULL)return -1;int s_len=strlen(source),c_len=strlen(chars);if(s_len < c_len) return -1;const char *p,*q;for(int i=0;i<s_len && s_len-i>=c_len;i++){p=source+i;q=chars;while( *p!='\0'&& *q!='\0' && *p==*q){q++;p++;}if(q >= chars + c_len) return i;}return -1;}int del_substr(char *str,char const *substr){if(str==NULL || substr==NULL)return -1;if('\0'==*str || '\0'==*substr)return -1;int str_len=strlen(str),substr_len=strlen(substr);if(str_len < substr_len) return -1;int first;if( (first=find_string(str,substr)) == -1) return -1;char *p_str=str,*p_before=str+first;char *p_after=p_before+substr_len;while(*p_before++ = *p_after++);return 1;}void reverse_string(char *string){if(string==NULL || *string=='\0') return ;int len=strlen(string);if(len==1) return ;char *before=string,*after=string+len-1;char temp;while( before < after ){temp=*before;*before=*after;*after=temp;before++;after--;}}int main(){char source[]="abcdefgdhjsdfkhsdfnbcxvndbfghijklnm\0";char value[]="jkln\0";int pos;pos=find_string(source , value);if(pos!=-1)printf("OK: %d\n",pos);else printf("NO\n");printf("\n");chars[]="123456789123456789123456789123456789123456789123456789123456789\0";int ok=del_substr(s,"");if(ok==1) printf("result = %s\n",s);else printf("NO\n");printf("\n");printf("source = %s\n",s);reverse_string(s);printf("result = %s\n",s);getch();return 0;}。