Reverse a String In-Place

Code

#include <stdio.h>

void reverse_string(char *str) {
    // Your logic here
    char* start=str;
    int len=0;
    

     while (*str!='\0'){
        len++;
        str++;
    }
    int copy=len;
    while (copy>0){
        str--;
        copy--;
    }

    for (int i=0;i<len/2;i++){
        char tmp;
        tmp=*str;
        *str=*(start+len-1-i);
        *(start+len-1-i)=tmp;
        str++;
    }
}

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;
}

Solving Approach