Advent-of-Code/2021/day13/solution-part2.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))

void printPaper( unsigned int width, unsigned int height, bool **paper ){
	for ( unsigned int y = 0; y < height; y++ ){
		printf("Line %i: ", y);
		for ( unsigned int x = 0; x < width; x++ ){
			if ( paper[x][y] == true ) printf("#");
			else printf(".");
		}
		printf("\n");
	}
}


bool** foldPaperX( unsigned int width, unsigned int height, unsigned int col, bool **paper){
	bool **newPaper=(bool**)malloc( col * sizeof(bool *));
	for(unsigned int x=0; x < col;x++) {
		newPaper[x]=(bool*)malloc( (height) *sizeof(bool));
		memset(newPaper[x], 0, sizeof(bool) * ( height ));
	}
	for ( unsigned int x = 1; x < width - col; x++ )
		for ( unsigned int y=0; y < height; y++ )
			newPaper[col - x][y] = paper[col - x][y] || paper[col + x][y];
	return newPaper;
}

bool** foldPaperY( unsigned int width, unsigned int height, unsigned int row, bool **paper){
	bool **newPaper=(bool**)malloc( (width) * sizeof(bool *));
	for(unsigned int x=0; x < width; x++) {
		newPaper[x]=(bool*)malloc( (row) *sizeof(bool));
		memset(newPaper[x], 0, sizeof(bool) * ( row ));
	}
	for ( unsigned int y=1; y < height - row; y++ )
		for ( unsigned int x = 0; x < width; x++ )
			newPaper[x][row - y] = ( paper[x][row - y] || paper[x][row + y] );
	return newPaper;
}

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

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

		unsigned int x=0,y=0,maxx=0,maxy=0;
		while ( fscanf( fp, "%i,%i\n",&x,&y )){
			maxx = MAX(maxx,x);
			maxy = MAX(maxy,y);
		}

		printf("Max x: %i Max y: %i\n", maxx, maxy);

		bool **paper=(bool**)malloc( (maxx+1) * sizeof(bool *));
		for(unsigned int i=0; i<=maxx;i++)
		{
			paper[i]=(bool*)malloc( (maxy+1) *sizeof(bool));
			memset(paper[i], 0, sizeof(bool) * ( maxy+1 ));
		}

		rewind(fp);
		while ( fscanf( fp, "%i,%i\n",&x,&y )){
			paper[x][y] = true;
		}

		printPaper( maxx+1, maxy+1, paper );
		printf("\n");


		char direction = '\0';
		unsigned int position = 0;
		while (!feof(fp) && fscanf(fp, "fold along %c=%i\n", &direction, &position)){
			printf("Trying to fold in %c direction at position %i\n", direction, position);
			if ( direction == 'x' ){
				paper = foldPaperX(maxx+1, maxy+1, position, paper);
				maxx = position - 1;
				printPaper( maxx + 1, maxy + 1, paper );
			} else {
				paper = foldPaperY(maxx+1, maxy+1, position, paper);
				maxy = position - 1;
				printPaper( maxx+1, maxy+1, paper );
			}
			
		}


		fclose(fp);

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