[C Language] Reverse string order

[C Language] Reverse string order

There are multiple methods to reverse string order. The following methods are used to convert strings: // non-recursive string inversion: char * reverse (char * str) {if (! Str) {return NULL;} int len = strlen (str); int I, j; char temp; for (I = 0, j = len-1; I <j; I ++, j --) {// character temp = str [I]; str [I] = str [j]; str [j] = temp;} return str;} int main () {char src [] = {"abcdef"}; char * pdest = reverse (src ); puts (src); return 0;} // recursion is a stack structure: # include <stdio. h> # include <assert. h> void reverse_string (const char * const string) {assert (string); if (* string = '\ 0') return; Else reverse_string (string + 1); // first press the character stack putchar (* string); // then output the characters in the first and second order} int main () {char string [20] = {0}; scanf ("% [^ \ n]", string); reverse_string (string); printf ("\ n "); return 0;}: (if other library functions are not required) # include <stdio. h> # include <assert. h> int my_strlen (const char * string) {assert (string); if (* string = '\ 0') {return ;} else return 1 + my_strlen (string + 1);} char * reverse_string (char * string, int len) {Assert (string); if (! String) {return NULL;} if (len> 1) {char tmp = string [0]; string [0] = string [len-1]; string [len-1] = '\ 0'; // The last character will not process reverse_string (string + 1, len-2) at next recursion; // recursive call, every call, reduce a string [len-1] = tmp;} return string;} int main () {char string [20] = {0 }; int len; scanf ("% s", string); len = my_strlen (string); reverse_string (string, len); printf ("% s \ n", string ); return 0 ;}