Reverse a String In-Place

Code

#include <stdio.h>

void swap(char *a, char *b){
    char tmp = *a;
    *a = *b;
    *b = tmp;
}

void reverse_string(char *str) {
    // Your logic here
    int r = 0;
    while (str[r] != '\0') {
        r++;
    }

    int l = 0;
    while(l < r){
        swap(&str[l],&str[r-1]);
        l++;
        r--;
    }
}

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