Advent-of-Code/2021/day14/solution-part1.c

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

#define ANSI_COLOR_RED     "\x1b[31m"
#define ANSI_COLOR_YELLOW  "\x1b[33m"
#define ANSI_COLOR_RESET   "\x1b[0m"

#define MAX(a, b) ((a) < (b) ? (b) : (a))
#define MIN(a, b) ((a) < (b) ? (a) : (b))


typedef struct Element Element;
struct Element{
	char letter;
	Element *next;
};

typedef struct Interaction Interaction;
struct Interaction{
	char letter1;
	char letter2;
	char result;
	Interaction *next;
};

Element* newElement(char letter){
	Element *new = malloc(sizeof(Element));
	new->letter = letter;
	new->next = NULL;
	return new;
}

Interaction* newInteraction(char letter1, char letter2, char result){
	Interaction *new = malloc(sizeof(Interaction));
	new->letter1 = letter1;
	new->letter2 = letter2;
	new->result = result;
	new->next = NULL;
	return new;
}

void printElements(Element *current){
	while ( current != NULL ){
		printf("%c ",current->letter);
		current = current->next;
	}
	printf("\n");
}

void printInteractions(Interaction *current){
	while ( current != NULL ){
		printf("Merging %c and %c will give you %c\n",current->letter1, current->letter2, current->result);
		current = current->next;
	}
	printf("\n");
}


unsigned int countElements(Element *current){
	unsigned int count = 0;
	while ( current != NULL ){
		count++;
		current = current->next;
	}
	return count;
}

Element* interact(char firstCh, char secondCh, Interaction *interaction){
	while ( interaction != NULL ){
		if ( interaction->letter1 == firstCh && interaction->letter2 == secondCh )
			return newElement( interaction->result );
		interaction = interaction->next;
	}
	return NULL;
}

unsigned int calculateScore(Element *current){
	unsigned int min = ~0;
	unsigned int max = 0;
	unsigned int counts[26] = {0};
	while ( current != NULL ){
		counts[current->letter - 'A']++;
		current = current->next;
	}
	for(unsigned int i = 0; i < 26; i++){
		max = MAX( max, counts[i] );
		if ( counts[i] != 0 ) min = MIN( min, counts[i] );
		printf("%c: %i\n", i+'A' , counts[i]);
	}
	printf("Max: %i, Min: %i, Difference: %i\n", max, min, max-min);
	return 0;
}

void step(Element *element, Interaction *interaction){
	while ( element != NULL && element->next != NULL ){
		Element *toInsert = interact(element->letter, element->next->letter, interaction);
		toInsert->next = element->next;
		element->next = toInsert;
		element = toInsert->next;
	}
}

int main( int argc, char *argv[] ){
	if( argc == 2 ) {


		FILE *fp=fopen(argv[1], "r");

		char ch;
		Element *firstEl = NULL;
		Element *previousEl = NULL;
		while ( fscanf( fp, "%c",&ch )){
			if ( ch == '\n' ) break;
			printf("%c\n",ch);
			if ( firstEl == NULL ){
				firstEl = newElement(ch);
				previousEl = firstEl;
			} else {
				previousEl->next = newElement(ch);
				previousEl = previousEl->next;
			}
		}


		//Skip over empty lines
		while( !feof(fp) && fscanf(fp, "\n\n") ) continue;

		char firstCh, secondCh, resultCh;
		Interaction *firstInt = NULL;
		Interaction *previousInt = NULL;
		while( !feof(fp) && fscanf(fp, "%c%c -> %c\n", &firstCh, &secondCh, &resultCh) ){
			if ( firstInt == NULL ){
				firstInt = newInteraction(firstCh, secondCh, resultCh);
				previousInt = firstInt;
			} else {
				previousInt->next = newInteraction(firstCh, secondCh, resultCh);
				previousInt = previousInt->next;
			}
		}



		printElements(firstEl);
		for ( unsigned int i = 0; i < 10; i++ ){
			printf("\nStep %i:\n", i+1);
			step(firstEl, firstInt);
			printf("Length %i\n", countElements(firstEl));
		}

		calculateScore(firstEl);

		fclose(fp);



		return 0;
	} else {
		printf("You need to provide a file\n");
		return 1;
	}
}