2022-day3b.c

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

int main(void)
{
	FILE *f;
	char line[1024];
	unsigned long sum = 0;
	f = fopen("day3.txt", "r");

	char sack1a[256];
	char sack1b[256];
	char sack1c[256];


	while(1)
	{
		memset(sack1a, 0, 256);
		memset(sack1b, 0, 256);
		memset(sack1c, 0, 256);


		if(!fgets(line, 128, f))
			break;
		if(line[0] == '\n')
			break;
		int i, len = strlen(line) - 1;
		for(i = 0; i < len; i++)
			sack1a[line[i]]=1;
		
		if(!fgets(line, 128, f))
			break;
		if(line[0] == '\n')
			break;
		len = strlen(line) - 1;
		for(i = 0; i < len; i++)
			sack1b[line[i]]=1;

		if(!fgets(line, 128, f))
			break;
		if(line[0] == '\n')
			break;
		len = strlen(line) - 1;
		for(i = 0; i < len; i++)
			sack1c[line[i]]=1;



		for(i = 0; i < 255; i++)
		{
			if(sack1a[i] && sack1b[i] && sack1c[i])
			{
				if(i >= 'a' && i <= 'z')
					sum += 1 + i - 'a';
				else
					sum += 27 + i - 'A';
				printf("sum: %lu, %c is in all 3: %s", sum, i, line);
			}
		}
	}

	printf("sum: %lu\n", sum);

	return 0;
}