字符串替换

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作者在 2008-10-25 00:36:41 发布以下内容

今天去面试，给了个题：
要求把字符串 “sdjaabcasdkk;3asd,abcadapabcadp” 中的子串“abc”使用 “zhong” 替代得到一个新的字符串
看着这个好像挺简单的，竟然花了我好长时间！！真是郁闷

#include <stdio.h>
#include <string.h>

char *source = "sadaabcadadjalabcdd";

int main()
{
 char dec[100] = {0};
 int i;
 char *pstr = source;
 char *pstr1 = dec;
 printf("%s\n",source);

 for (i=0;i<(signed)strlen(source);i++)
 {
 if (0==strncmp(pstr,"abc",3))
 {
 strcat(dec,"zhong");
 pstr += strlen("abc");
 pstr1 += strlen("zhong");
 }
 else
 {
 dec[(pstr1-dec)] = *pstr;
 dec[(pstr1-dec)+1] = 0;
 pstr += 1;
 pstr1 += 1;
 }
 }

 printf("%s\n",dec);
 return 0;

}
上面是我的答案，希望和大家一起探讨下，由什么更加高效的算法

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文章评论，共6条

vfdff(作者)

2008-10-25 07:52

C格式字符串转string可以直接转 
string str; 
str = "Hello World!"; 
 
string转C格式 
string str = "Hello World!"; 
char *str = str.c_str();

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vfdff(作者)

2008-10-25 13:55

改进算法： 
#include <stdio.h> 
// #include <string.h> 
#include <string> 
#include <iostream> 
 
const char *source = "sadaabcadadjalabcdd"; 
 
int main() 
{ 
    std::string target; 
    int i; 
    const char *pstr = source; 
    printf("%s\n",source); 
 
    for (i=0;i<(signed)strlen(source);i++) 
    { 
        if (0==strncmp(pstr,"abc",3)) 
        { 
            target += "zhong"; 
            pstr += strlen("abc"); 
        } 
        else 
        { 
            target += *pstr; 
            pstr += 1; 
        } 
    } 
 
    std::cout <<target <<std::endl; 
    // printf("%s\n",target.c_str()); // 不能直接使用printf("%s\n",target); 
    return 0; 
 
}

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shan_0823

2008-11-12 14:48

void test2() 
{ 
    char *source = "sadaabcadadjalabcdd"; 
    char dec[100] = {0}; 
    int i; 
    char *pstr = source; 
    char *pstr1 = dec; 
    printf("%s\n",source); 
 
    for (i=0;i<(signed)strlen(source);i++) 
    { 
        if (0==strncmp(pstr,"abc",3)) 
        { 
            strcat(pstr1,"zhong"); 
            pstr += strlen("abc"); 
            pstr1 += strlen("zhong"); 
        } 
        else 
          *pstr1++ = *pstr++; 
    } 
    *pstr1 = 0; 
    printf("%s\n",dec); 
} 
 
改进后充分利用指针的优势..

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vfdff(作者)

2008-11-13 00:44

<div class="quote">shan_0823: void test2() {     char *source = "sadaabcadadjalabcdd";     char dec = {0};   &nbs</div>恩，不错，谢谢指教

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vfdff(作者)

2008-11-14 19:40

// 将 shan_0823: 的指针操作版本修改为数组操作 
 
#include <stdio.h> 
#include <string.h> 
 
char *source = "sadaabcadadjalabcdd"; 
 
int main() 
{ 
    char dec[100] = {0}; 
    int i; 
    //char *pstr = source; 
    //char *pstr1 = dec; 
    char pstr=0,pstr1=0; 
    printf("%s\n",source); 
 
    for (i=0;i<(signed)strlen(source);i++) 
    { 
        if (0==strncmp(source+pstr,"abc",3))  // 地址值source+pstr 
        { 
            strcat(dec,"zhong"); 
            pstr += strlen("abc"); 
            pstr1 += strlen("zhong"); 
        } 
        else 
        { 
            dec[pstr1++] = source[pstr++]; 
        } 
        dec[pstr1] = 0; 
    } 
    printf("%s\n",dec); 
    return 0; 
}

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vfdff(作者)

2010-07-02 20:41

#include <stdio.h> 
#include <string.h> 
//#include <string> 
 
char* source = "sadaabcadadjalabcdd"; 
char dec[1024] = {0}; 
    
 
// 把字符串str中的子字符串substr1用子字符串substr2替换 
char* SwapSubstr(char *dest, char *source, char*substr1, char*substr2) 
{ 
    char *pstr = source; 
    char *pstr1 = dest; 
    unsigned int i; 
    
    for (i=0;i<strlen(source)-strlen(substr1)+1;i++) 
    { 
        if (0==strncmp(pstr,substr1,strlen(substr1))) 
        { 
            strcat(pstr1,substr2); 
            pstr += strlen(substr1); 
            pstr1 += strlen(substr2); 
        } 
        else 
            *pstr1++ = *pstr++; 
    } 
    *pstr1 = 0; 
    return dest; 
} 
 
int main() 
{ 
    printf("++%s\n", SwapSubstr(dec, source, "abc", "zhong")); 
    return 0; 
} 
 
封装成子函数

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