反转字符串的多种方式-经典面试题系列

#include "stdafx.h"
#include "stdio.h"
#include "stdlib.h"
#include "string.h"

char *t1(const char *str)
{
const size_t len = strlen(str);
char *temp = (char *)malloc(sizeof(char) * len);
strcpy(temp,str);
for(size_t i=0; i<= len/2; i++)
{
char c = temp[i];
temp[i] = temp[len -i - 1];
temp[len - i - 1] = c;
}
return temp;
}

char *t2(const char* str)
{
char *tmp = (char *)malloc(sizeof(char) * strlen(str));
strcpy(tmp,str);

char *ret = tmp; //用来返回最后的数组,不能直接返回tmp，因为最后tmp的位置发生了变化
char *p = tmp + strlen(str) - 1; //字符串最后一位
while(p > tmp)
{
char c = *tmp;
*tmp++ = *p;
*p-- = c;
}
return ret;
}

int main(int argc, char* argv[])
{
char *str1 = "hello world";
char *ret = t2(str1);
printf("%s\n",ret);
return 0;
}