Reverse a String In-Place

#include <stdio.h>
 
int SIZEOF(char *str){
    int i = 0; 
    while(*(str + i) != '\0'){
         i++;
    }
    return i;
}
void reverse_string(char *str) {
    // Your logic here
    char *start = str;
    char *end = str + (SIZEOF(str) - 1);
    while(start < end){
        char ram;
        ram = *end;
        *end = *start;
        *start = ram;
        start++;
        end--;
    }
}

int main() {
    char str[101];
    fgets(str, sizeof(str), stdin);

    // Remove newline
    int i = 0;
    while (str[i] != '\0') {
        if (str[i] == '\n') {
            str[i] = '\0';
            break;
        }
        i++;
    }

    reverse_string(str);
    printf("%s", str);
    return 0;
}