删除指定字符串

编写函数DelStr(str1,str2)。其中str1和str2为两个字符串。函数的功能是从str1中删除所有str2字串，结果由str1输出。函数没有返回值。例如，输入str1为“howareyouareGGGare”,str2为“are”，那么调用函数DelStr(str1,str2)后str1为“howyouGGG”

 

字符串基本功练手代码。codepad.org已验证。

一个比较复杂的字符串函数，从思考到完成25分钟左右。虽然代码写的傻但是一次无bug过。值得撒花，几个月来没有白练。

 

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#define SWAP(a,b) a^=b;b^=a;a^=b

char* mydelstr(char* src, const char* del){
    if(src == NULL || !*src|| del==NULL || !*del) return src;
    char* ret = src;
    int dellen = strlen(del);
    int srclen = strlen(src);
    char* pEmpty = NULL;
    char* pChar = NULL;
    //replace the target with \0
    while( (src = strstr(src, del))!=NULL){
        int i = 0;
        if(pEmpty == NULL)
            pEmpty = src;
        for(;i<dellen; i++)
            src[i]='\0';
        src+=dellen;
        if(pChar == NULL)
            pChar = src;
    }

    //re-orgnize
    int i = 0;
    while(pEmpty!=NULL && pChar!=NULL && *pChar){
        SWAP(*pEmpty, *pChar);
        while(*pEmpty!='\0') pEmpty++;
        while(*pChar=='\0' && pChar<ret+srclen) pChar++;
        if(pChar == ret+srclen)
            break;
    }
    return ret;
}

int main(){
    char src1[] = "abcdbce";
    char* del1 = "bc";
    char src2[] = "abc";
    char src3[] = "a";
    char src4[] = "bc";

    printf("case 1:%s \n", mydelstr(src1, del1));
    printf("case 2:%s \n", mydelstr(src2, del1));
    printf("case 3:%s \n", mydelstr(src3, del1));
    printf("case 4:%s \n", mydelstr(src4, del1));
    printf("------------end----------");
}