Reverse a String In-Place

Code

#include <stdio.h>

void reverse_string(char *str) {
    char t;
    int i = 0;

    while(str[i])
        i++;

    int j = 0;
    i--;

    while(j < i)
    {
        t = str[j];
        str[j] = str[i];
        str[i] = t;
        j++, i--;
    }
}

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