Reverse a String In-Place

Code

#include <stdio.h>

void reverse_string(char *str) {
    int start=0;
    int end=0;
    while(*(str+end) != '\0'){
        end++;
    }
    end--;
    while(start < end){
        char temp = *(str+start); 
        *(str+start) = *(str+end);
        *(str+end) = temp;
        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;
}

Solving Approach