Reverse a String In-Place

Code

#include <stdio.h>

void reverse_string(char *str) {
    // Your logic here
    char *end = str;

    for (; *end != '\0'; ++end);

    // end is str null not the last char
    --end;

    while (str < end) {
        char tmp = *str;
        *str = *end;
        *end = tmp;

        ++str;
        --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;
}

Solving Approach