EE2 Exercises

.gitignore

*.o
main
main.exe

l0320112.c

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

#include "lib.h"

static void q1() {
    /* No original, o acumulador foi definido no escopo errado (dentro do 'for' em vez de fora) */
    int s = 0;
    for (int i = 1; i < 10; i++)
        s += i*i;
    printf("%d\n", s);
}

static void q2() {
    srand((unsigned) time(0));
    int face[6];
    memset(&face[0], 0, 6 * sizeof(int));
    for (int i = 0; i < 1200; i++)
        ++face[rand()%6];

    char *face_names[] = {
        "   Um   ",
        "  Dois  ",
        "  Tres  ",
        " Quatro ",
        " Cinco  ",
        "  Seis  " };
    printf("  Face    Observacoes\n");
    for(int i = 0; i < 6; i++) {
        printf("%s      %d\n", face_names[i], face[i]);
    }
}

void lista_03() {
	char  *names[] = { "Corrigido", "Dados" };
	func_t funcs[] = { &q1, &q2 };
	int choice = menu("Lista 03.2011.2", 2, names);
	funcs[choice]();
}

l0420112.c

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

#include "lib.h"


void lista_04() {
    int opt = menu("Usar srand(time(NULL))", 2, (char*[]) { "Sim", "Nao" });
	srand(opt == 1 ? 0 : time(NULL));
    for(int i = 0; i < 26; i++)
        printf("%c%s", rand()%26 + 'a', i == 25 ? "\n" : " ");
}

l0520112.c

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

#include "lib.h"

static void q1() {
	for (int i = 0x20; i <= 0xff; i++) {
		printf("dec: %02d -- hex: %02x -- char: %c\n", i, i, (char)i);
	}
}

static void q2() {
	int chr;
	int alloc_mult = 1;
	char *buf = malloc(alloc_mult * 255);
	char *pos = buf;
	while ((chr = fgetc(stdin)) != 0x1B) {
		*pos++ = (char) chr;
		if (pos - buf > alloc_mult * 255 - 2) {
			int distance = pos - buf;
			buf = realloc(buf, ++alloc_mult * 255);
			pos = buf + distance;
		}
	}
	*pos = 0;
	for (char *c = buf; c != pos; c++) {
		printf("%c", toupper((int) *c));
	}
	printf("\n");
	fflush(stdout);
}

static void q3() {
	long term;
	ask("Numero do termo da seq. de Fibonacci", ASK_LONG, 0, &term);
	printf("%ld\n", fib(term));
}

static void q4() {
	int mode = menu("", 2, (char*[]){ "Combinacao", "Permutacao" });
	long n, r;
	ask("Numero total de objetos", ASK_LONG, 0, &n);
	ask("Quantos por vez", ASK_LONG, 0, &r);

	if (n < 0 || r < 0) {
		fprintf(stderr, "Nao e possivel formar um conjunto negativo.\n");
		return;
	}
	if (r > n) {
		fprintf(stderr, "Nao e possivel remover mais objetos do que existem.\n");
		return;
	}

    printf("%ld\n", mode == 1 ? combine(n, r) : permute(n, r));
}

void lista_05() {
	char  *names[] = { "ASCII", "toupper", "Fibonacci Iterativo", "Combinacao / Permutacao" };
	func_t funcs[] = { &q1, &q2, &q3, &q4 };
	int choice = menu("Lista 05.2011.2", 4, names);
	funcs[choice]();
}

l0620112.c

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

#include "lib.h"

static void q1() {
    long n;
    ask("Numero de termos", ASK_LONG, 0, &n);

    if (n > 0)
        printf("1");

    long acc = 1, prev = 0;
    for (int i = 1; i < n; i++) {
        acc += prev;
        prev = acc - prev;
        printf(" %ld", acc);
    }
    printf("\n");
}

static void q2() {
    int opt = menu("Triangulo de Pascal", 2, (char*[]) { "Imprimir triangulo", "Calcular soma de linha especifica" });
    long n;
    ask(opt ? "Linha do triangulo" : "Ordem to triangulo", ASK_LONG, 0, &n);
    if (opt) {
        printf("Soma da linha %ld: %ld\n", n, (long) pow(2, n-1));
    } else {
        for (int i = 0; i <= n; i++) {
            for (int j = 0; j <= i; j++) {
                printf("%5ld%s", combine(i, j), i == j ? "\n" : " ");
            }
        }
    }
}

void lista_06() {
	char  *names[] = { "Fibonacci", "Pascal" };
	func_t funcs[] = { &q1, &q2 };
	int choice = menu("Lista 06.2011.2", 2, names);
	funcs[choice]();
}

l0720112.c

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

#include "lib.h"

void lista_07() {
	char in_str[512], in_ch_str[2];
	
	ask("Digite uma sentenca", ASK_STRING, 511, &in_str[0]);
	do {
		ask("Digite um caractere", ASK_STRING, 1, &in_ch_str[0]);
	} while (strlen(in_ch_str) < 1);
	in_str[511] = 0;
	int l = strlen(in_str);
	if (in_str[l-1] == '\n')
		in_str[l-1] = 0; // remove o \n
	in_ch_str[1] = 0;
	
	int count = 0;
	char *first = NULL;
	char *ptr = &in_str[0];
	while ((ptr = strstr(ptr, in_ch_str))) {
		if (!first) first = ptr;
		++count;
		++ptr;
	}
	
	if (count) {
		printf("O caractere '%s' pertence a sentenca.\n", in_ch_str);
		printf("O caractere aparece '%d' vezes.\n", count);
		printf("Sua primeira ocorrencia e na posicao '%d'.\n", (int)(first - &in_str[0]));
		printf("A sentenca a partir da primeira ocorrencia e: '%s'.\n", first);
	} else {
		printf("O caractere '%s' nao ocorre na sentenca.\n", in_ch_str);
	}
}

lib.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "lib.h"

int ask(char *prompt, AskType ask_type, int maxlen, void *out)
{
	char temp_buf[256];
    char *bool_prompt = "";
    if (ask_type == ASK_BOOL)
        bool_prompt = " [s/n]";

	while (1) {
		fprintf(stderr, "%s%s: ", prompt, bool_prompt);
		fflush(stderr);
		if (!fgets(temp_buf, 256, stdin)) {
			return -1;
		}
		switch (ask_type) {
		case ASK_STRING: {
			int len, total_len = 0;
			char *out_pos = out;

			while (maxlen > total_len && (len = strlen(temp_buf)) == 255) {
				strncpy(out_pos, &temp_buf[0], maxlen - total_len);
				total_len += len;

				if (!fgets(temp_buf, 256, stdin)) {
					return -2;
				}
			}
			if (maxlen > total_len)
				strncpy(out_pos, &temp_buf[0], maxlen - total_len);
			return total_len + len - 1;
		}
		case ASK_LONG: {
			long res;
			char *temp_buf_end;
			res = strtol(temp_buf, &temp_buf_end, 0);
			if (*temp_buf_end != '\n') {
				if (*temp_buf_end == '\0') {
					fprintf(stderr, "Numero muito longo\n");
					while (fgetc(stdin) != '\n') {} // discard rest of input line
				}
				else
					fprintf(stderr, "Numero invalido\n");
				continue;
			}
			*(long*)out = res;
			return 0;
		}
		case ASK_FLOAT: {
			float res;
			char *temp_buf_end;
			res = (float) strtod(temp_buf, &temp_buf_end);
			if (*temp_buf_end != '\n') {
				fprintf(stderr, "Numero invalido\n");
				continue;
			}
			*(float*)out = res;
			return 0;
		}
        case ASK_BOOL: {
            char ans = tolower((int) temp_buf[0]);
            if (strlen(temp_buf) != 1 || (ans != 's' && ans != 'n')) {
                fprintf(stderr, "Resposta invalida\n");
                continue;
            }
            if (out)
                *(int*)out = ans == 's';
            return ans;
        }
		default:
			fprintf(stderr, "Internal error: invalid AskType\n");
			exit(50);
		}
	}
}

long menu(char *title, int optcount, char **options) {
	long o = -1;

	fprintf(stderr, "Menu: %s\n", title);
	for (int i = 0; i < optcount; i++) {
		fprintf(stderr, "  %d. %s\n", i+1, options[i]);
	}
	int res;
	while (!(res = ask("Escolha", ASK_LONG, 0, &o)) && (o < 1 || o > optcount)) {
		fprintf(stderr, "Numero invalido\n");
	}
	if (res < 0)
		exit(-res);

	return o - 1;
}

long fib(int n) {
    long acc = 1, prev = 1;
    for(int i = 2; i < n; i++) {
        acc += prev;
        prev = acc - prev;
    }
    return acc;
}

long fac(int n) {
	long acc = 1;
	for(long next = n; next > 1; next--)
		acc *= next;
	return acc;
}

long combine(int n, int k) {
    return fac(n) / fac(k) / fac(n - k);
}

long permute(int n, int k) {
    return fac(n) / fac(n - k);
}

lib.h

#ifndef _LIB_H_
#define _LIB_H_

typedef void (*func_t)();

typedef enum {
	ASK_STRING,
	ASK_LONG,
	ASK_FLOAT,
    ASK_BOOL
} AskType;

int ask(char *prompt, AskType ask_type, int maxlen, void *out);

/* Exibe menu com titulo "title", numero "optcount" de opcoes
   e texto das opcoes em "options". Retorna o indice de "options"
   que foi selecionado. */
long menu(char *title, int optcount, char **options);

long fib(int n);

long fac(int n);

long combine(int n, int k);

long permute(int n, int k);

#endif // _LIB_H_

main.c

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

extern void lista_03();
extern void lista_04();
extern void lista_05();
extern void lista_06();
extern void lista_07();
extern void lista_08();

static void main_exit() {
    exit(0);
}

int main() {
	char  *names[] = { "03.2011.2", "04.2011.2", "05.2011.2", "06.2011.2", "07.2011.2", "08.2011.2", "Sair" };
	func_t funcs[] = { &lista_03, &lista_04, &lista_05, &lista_06, &lista_07, &lista_08, &main_exit };
    while (1) {
        int choice = menu("Listas de Exercicios", 7, names);
        funcs[choice]();
        printf("\n\n");
    }
}

Makefile

CC = gcc
CFLAGS = -std=c99

OBJS = l0320112.o \
       l0420112.o \
       l0520112.o \
       l0620112.o \
       l0720112.o \
       l0820112.o \
       lib.o

all: main lista_08_2


main: $(OBJS)

lista_08_2: lista_08_2.o lib.o