How to reverse string in C

reverse_str.c

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

// My solution
void rvrs(char * str, char * reversed_str, unsigned len) {
    str += len - 1; 
    while (str[0]) {
        *reversed_str = str[0];
        str -= 1;
        reversed_str++;
    }
}

// I found this solution somewhere from internet 
char *strrev (char *string) {
  unsigned len = strlen(string); 
  int tmp;  
  
  for (unsigned idx = 0; idx < len/2; idx++) {  
    tmp = string[idx];  
    string[idx] = string[len - idx - 1];  
    string[len - idx - 1] = tmp;  
  }   
  
  return string; // reverse the string in place and return it
}