Reverse a String In-Place

Code

#include <stdio.h>
#include <string.h>
void reverse_string(char *str) {
    int start=0;
    int end=strlen(str)-1;
    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);   
    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