c - 在 C 中编写程序来反转字符串中的单词时遇到问题

Question

我正在尝试编写一个小程序来反转字符串中的单词(经典面试问题)，但遇到了一些障碍。在该网站的另一部分，我发现了一种非常酷的方法来使用按位运算来反转字符串，所以我尝试使用一个程序，它只使用一个 reverse() 来反转整个字符串，然后是子串。

不幸的是，我的程序只会反转第一个子字符串，我很难找出原因。任何帮助将不胜感激。

#include<stdlib.h>
#include<stdio.h>
#include<string.h>
void reverse(char string[], int beg, int end) {
  int length = end-beg-1;
  for(int i=beg; i < length/2; i++) {
    string[i] = string[i] ^string[length-i];
    string[length-i] = string[i] ^ string[length - i];
    string[i] = string[i] ^string[length-i];
  }

 }

int main (int argv, char * arrv[]) {
   int beg, end;
   char string[] = "This is the string to reverse";
   int length = strlen(string);
   printf("%s\n", string);
   printf("%d\n", length);
 //reverse whole string
   reverse(string, 0, length);
   printf("%s\n", string);
   beg =0;
   end = 0;
  //reverse strings at index's beg and end
    for(int i = 0; i <= length-1; i++) {
      if (string[i] == ' ') {                                      
       reverse(string, beg, end);
       beg = i+1;  
     }
     end++;
     printf("%s\n", string);
   }
   printf("%s\n", string);
    return 1;
}

谢谢IE预期输出:反向字符串 the is this我的输出:reverse ot gnirts eht si siht

Answer 1

加上@alexd 的建议，以下是更新后的程序，并进行了一些修复:

#include<stdlib.h>
#include<stdio.h>
#include<string.h>
void reverse(char string[], int beg, int end) {
    int length = end - beg;
    for (int i = 0; i < length / 2; i++) {
        string[beg + i] = string[beg + i] ^ string[end - 1 - i]; 
        string[end - 1 - i] = string[beg + i] ^ string[end - 1 - i]; 
        string[beg + i] = string[beg + i] ^ string[end - 1 - i]; 
    }   
}

int main (int argv, char * arrv[]) {
   int beg, end;
   char string[] = "This is the string to reverse";
   int length = strlen(string);
   printf("%s\n", string);
   printf("%d\n", length);
 //reverse whole string
   reverse(string, 0, length);
   printf("%s\n", string);
   beg =0; 
   end = 0;
  //reverse strings at index's beg and end
    for(int i = 0; i <= length-1; i++) {
      if (string[i] == ' ') {    
       reverse(string, beg, end);
       beg = i+1;  
       printf("%s %d %d\n", string, beg, end);
     } else if(i==length-1) {
       end = length;
       reverse(string, beg, end);
     }   
     end++;
 }
   printf("%s\n", string);
    return 1;
}