[Proggyak I] Betűszűrő

betuszuro.c

/**
 * Betuszuro
 *
 * Beker ket szot, es kiirja azokat a karaktereket,
 * melyek csak az elsoben szerepelnek
 *
 * @todo source_unique and source_filter violates DRY.
 */

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

/**
 * Get source length
 *
 * @param char source[] source
 * @return sources length
 */
int source_length(char source[]) {
	int i = 0;
	while (source[i]) { i++; }
	return i;
}

/**
 * Makes all char unique in source
 *
 * @param char source[] source
 * @todo refactor into source_filter
 */
void source_unique(char source[]) {
	int length, i = 0, j, newchar = 0, uindex = 0;
	char *unique = NULL;

	length = source_length(source);

	unique = (char *)malloc(length * sizeof(char) );

	while (source[i]) {
		newchar = 1;

		for(j = i-1; j >= 0; j--) {
			if (source[j] == source[i]) {
				newchar = 0;
			}
		}

		if (newchar) {
			unique[uindex] = source[i];
			uindex++;
		}

		i++;
	}
	unique[uindex] = '\0';

	i = 0;
	while (unique[i]) {
		source[i] = unique[i];
		i++;
	}
	source[i] = '\0';
	free(unique);
}

/**
 * Looks for filter's characters in source and removes them.
 *
 * @param char source[] source
 * @param char filter[] characters to filter out
 */
void source_filter(char source[], char filter[]) {
	int slength, flength, i = 0, j, passed = 0, findex = 0;
	char *filtered = NULL; //chars passed the filter

	slength = source_length(source);
	flength = source_length(filter);


	filtered = (char *)malloc(slength * sizeof(char) );

	while (source[i]) {
		passed = 1;

		for(j = 0; j < flength; j++) {
			if (source[i] == filter[j]) {
				passed = 0;
			}
		}

		if (passed) {
			filtered[findex] = source[i];
			findex++;
		}

		i++;
	}
	filtered[findex] = '\0';

	i = 0;
	while (filtered[i]) {
		source[i] = filtered[i];
		i++;
	}
	source[i] = '\0';
	free(filtered);
}

/**
 * Prints source's characters
 * separated by spaces
 *
 * @param char source[] source to print
 */
void source_print(char source[]) {
	int i = 0;
	while (source[i]) {
		printf("%c ", source[i]);
		i++;
	}
	if (i == 0) {
		//source is empty
		printf("Nincsenek ilyen betuk");
	}
}

/**
 * Betuszuro
 */
int main() {
	char source[128], filter[128];

	printf("Elso szo, mely azon betuit keressuk...\n");
	scanf("%s", source);

	printf("...melyek nincsenek benne a masodik szoban:\n");
	scanf("%s", filter);

	source_unique(source);
	source_filter(source, filter);

	printf("A kovetkezo betuk felelnek meg a felteteleknek\n");
	source_print(source);
	printf("\n");

	return 0;
}