utility.c

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// Copyright (C) 2025  Giulio Salvi, Jacopo Paradisi
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

 
#include "utility.h"
 
char* substring(const char* string, int startPosition, int length) {
    if (startPosition < 0 || length < 0 || startPosition + length > strlen(string)) {
        return NULL; 
    }
 
    char* sub = (char*)malloc(length + 1);
    if(sub == NULL)
        exit(EXIT_ALLOC_FAILURE);
 
    strncpy(sub, string + startPosition, length);
    sub[length] = '\0';
 
    return sub;
}
 
int offsetFromNext(const char* string, char character, int startPosition) {
    int strLen = strlen(string);
    if(startPosition < 0 || startPosition >= strLen)
        return -1;
 
    for(int i = startPosition; i < strLen; i++)
        if(string[i] == character)
            return i - startPosition;
    
    return -1;
}
 
int count(const char* string, char character, int startPosition) {
    int strLen = strlen(string);
    if(startPosition < 0 || startPosition >= strLen)
        return 0;
 
    int counter = 0;
    for(int i = startPosition; i < strLen; i++)
        if(string[i] == character)
            counter++;
 
    return counter;
}
 
bool containsFrom(const char* string, char character, int startPosition) {
    int strLen = strlen(string);
    if(startPosition < 0 || startPosition >= strLen)
        return false;
 
    for(int i = startPosition; i < strLen; i++)
        if(string[i] == character)
            return true;
    
    return false;
}
 
bool containsSubstringFrom(const char* string, const char* subString, int startPosition) {
    if(strcmp(string, subString) == 0)
        return true;
    
    int strLen = strlen(string);
    int subStrLen = strlen(subString);
    
    if(startPosition < 0 || startPosition >= strLen || subStrLen == 0 || subStrLen > strLen - startPosition)
        return false;
 
    for(int i = startPosition; i < strLen; i++)
        if(string[i] == subString[0] && i + subStrLen < strLen)
            for(int j = 0; j < subStrLen; j++) {
                if(string[i + j] != subString[j])
                    break;
                else if(j == subStrLen - 1)
                    return true;
            }
        
    return false;
}
 
bool isDecimalDigit(char character) {
    return character >= '0' && character <= '9';
}
 
bool isHexDigit(char character) {
    return isDecimalDigit(character) || (character >= 'a' && character <= 'f') || (character >= 'A' && character <= 'F');
}
 
int decimalDigitToInt(char digit) {
    return (int)(isDecimalDigit(digit) ? digit - '0' : digit);
}
 
int hexDigitToInt(char digit) {
    return isDecimalDigit(digit) ?
        decimalDigitToInt(digit) :
        (
            isHexDigit(digit) ?
            (
                digit >= 'a' ?
                (int)(digit - 'a') + 10 :
                (int)(digit - 'A') + 10
            ) :
        (int)digit
    );
}
 
int evalutateBase(char* number) {
    char max = -1;
 
    for(int i = 0; i < strlen(number); i++) {
        if(isHexDigit(number[i])) {
            if(number[i] > max)
                max = number[i];
        } else
            return -1;
    }
 
    return hexDigitToInt(max) + 1;
    
}
 
int nDigits(int number) {
    return number == 0 ? 1 : (int)log10(abs(number)) + 1;
}