Solution to Hackerrank's camel case 4 in C

camelcase.c

// # Enter your code here. Read input from STDIN. Print output to STDOUT
// # Each line of the input file will begin with an operation (S or C) followed by a semi-colon followed by M, C, or V

// # The operation will either be S (split) or C (combine)
// # M indicates method, C indicates class, and V indicates variable

// # In the case of a split operation, the words will be a camel case

// # In the case of a combine operation, the words will be a space-delimited list of words starting with lowercase letters that you need to combine into the appropriate camel case String

// # Methods should end with an empty set of par

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>


// trim from start (in place)
static inline void ltrim(char *s) {
    while (isspace(*s)) {
        s++;
    }
}

// trim from end (in place)
static inline void rtrim(char *s) {
    char *back = s + strlen(s);
    while (isspace(*--back));
    *(back + 1) = '\0';
} 

// trim from both ends (in place)
static inline void trim(char *s){
    ltrim(s);
    rtrim(s);
}

void addSpaceBeforeCapital(char *str) {
    int length = strlen(str);
    char result[2 * length]; // To accommodate possible additional spaces
    
    int resultIndex = 0;
    for (int i = 0; i < length; i++) {
        result[resultIndex++] = str[i];
        if (i > 0 && isupper(str[i + 1])) {
            result[resultIndex++] = ' ';
        }
    }
    result[resultIndex] = '\0'; // Null-terminate the result
    
    strcpy(str, result); // Copy the result back to the original string
}

int main() {
    char line[1000];
    while (fgets(line, sizeof(line), stdin)) {
        //split line
        char action = line[0];
        char mvcn = line[2];
        char s[1000];
        strcpy(s, line + 4);
        
        // start
        if (action == 'S') {
            if (mvcn == 'M') {
                s[strlen(s) - 3] = '\0';
            } else if (mvcn == 'C') {
                s[0] = tolower(s[0]);
            }
            char *s1 = " ";
            addSpaceBeforeCapital(s);
            for (int i = 0; i < strlen(s); i++) {
                if (s[i] >= 'A' && s[i] <= 'Z'){
                    
                    s[i] = tolower(s[i]);
                    
                    
                }
            }
        } else if (action == 'C') {
            char *space;
            while ((space = strchr(s, ' '))) {
                *space = toupper(*(space + 1));
                memmove(space + 1, space + 2, strlen(space + 1));
            }
            if (mvcn == 'M') {
                strcat(s, "()");
            } else if (mvcn == 'C') {
                s[0] = toupper(s[0]);
            }
        }
        
        trim(s);
        printf("%s\n", s);
    }
    return 0;
}