I am trying to build a program that could add up binary numbers, of arbitrary length, separated by a whitespace. I don't want to be limited by a maximum number length, therefore I'm doing everything without built-in number types, only chars. I read the numbers from a file. I perform everything on stack. I can't loop the part where I read and add numbers. My guess is that it's because I can't find a way to distinguish new line from EOF. The program works this way: I read first number and save it into first stack, then I read second number and save in second stack. Then I add it up, save into third stack and transfer it to first stack. I read next number, save it into second stack, add up and so on. So I basically want to loop the second reading and summing. Here is the source code part:
while( !isspace(c=(char)getc(ifp))) {
if( c == '0' || c == '1'){
if(!push(&a , c)){
clearStack(&a);
printf("alloc error");
return 0;
}
}else{
clearStack(&a);
printf("error1");
return 0;
}
}
if( a.size == 0 ){
printf("error2");
return 0;
}
while (!feof(ifp)) {
while( !isspace(c=(char)getc(ifp))) {
if( c == '0' || c == '1'){
if(!push(&b , c)){
clearStack(&a);
clearStack(&b);
printf("alloc error");
return 0;
}
}
else{
//clearStack(&a);
//clearStack(&b);
printf("error3");
//return 0;
}
}
if( b.size == 0 ){
if (a.size == 0){
printf("error4");
}
}
topA = a.size;
topB = b.size;
carry = 0;
while( topA > 0 || topB > 0) {
if ( ( topA > 0 ) ){
topA--;
if(a.data[topA] == '1'){
x = 1;
}else{
x = 0;
}
}else{
x = 0;
}
if ( ( topB > 0 ) ){
topB--;
if(b.data[topB] == '1'){
y = 1;
}else{
y = 0;
}
}else{
y = 0;
}
sum = x + y + carry;
if (sum == 2 || sum == 3){
carry = 1;
}else{
carry = 0;
}
if (sum == 1 || sum == 3) {
c = '1';
}else{
c = '0';
}
if(!push(&output , c)){
clearStack(&a);
clearStack(&b);
clearStack(&output);
printf("alloc error");
return 0;
}
}
if (carry == 1) {
if(!push(&output , '1')){
clearStack(&a);
clearStack(&b);
clearStack(&output);
printf("alloc error");
return 0;
}
}
clearStack(&a);
for (i=0; i < output.size; i++){
push(&a , output.data[i]);
}
clearStack(&b);
clearStack(&output);
} /*end of EOF while*/
For some reason, although it reads multiple times, it reads wrong and works only for 2 numbers. The file looks like this: "1 1", but when its "1 1 1" it will just add first 2 numbers. I don't know where am I making a mistake. Below I attach the whole source code. I invoke the program in console like this: ./program file. I know that the case is poorly described but can't do it in a better manner, I will add comments if anything is needed.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
struct stack {
char *data;
int size;
};
int push(struct stack * s, char c){
char * newData = (char *)realloc( s->data , (s->size + 1) * sizeof(char));
if( newData ){
s->data = newData;
s->data[s->size]=c;
s->size++;
return 1;
}else{
return 0;
}
}
/* not needed */
char pop(struct stack * s){
if(s->size > 0){
char result = s->data[s->size-1];
char * newData = (char *)realloc( s->data , s->size - 1);
if( newData ){
s->data = newData;
s->size--;
return result;
}else{
return 0;
}
}
else{
return 0;
}
}
struct stack newStack(){
struct stack s;
s.data = NULL;
s.size = 0;
return s;
}
void clearStack(struct stack * s){
free(s->data);
s->data = NULL;
s->size = 0;
}
int main (int argc, char const * argv[])
{
struct stack a = newStack();
struct stack b = newStack();
int topA, topB, x , y, carry, sum,i , start;
struct stack output = newStack();
char c;
FILE *ifp;
if(argc!=2){printf("Usage: ./a.out input_file."); return(1);}
if(!(ifp = fopen(argv[1], "r"))){printf("Unable to open input file!"); return(2);}
while( !isspace(c=(char)getc(ifp))) {
if( c == '0' || c == '1'){
if(!push(&a , c)){
clearStack(&a);
printf("alloc error");
return 0;
}
}else{
clearStack(&a);
printf("error1");
return 0;
}
}
if( a.size == 0 ){
printf("error2");
return 0;
}
while (!feof(ifp)) {
while( !isspace(c=(char)getc(ifp))) {
if( c == '0' || c == '1'){
if(!push(&b , c)){
clearStack(&a);
clearStack(&b);
printf("alloc error");
return 0;
}
}
else if (c == '\0' || c == ' ' || c == '\n'){
}
else{
//clearStack(&a);
//clearStack(&b);
printf("error3");
//return 0;
}
}
if( b.size == 0 ){
if (a.size == 0){
printf("error4");
//return 0;
}
}
topA = a.size;
topB = b.size;
carry = 0;
while( topA > 0 || topB > 0) {
if ( ( topA > 0 ) ){
topA--;
if(a.data[topA] == '1'){
x = 1;
}else{
x = 0;
}
}else{
x = 0;
}
if ( ( topB > 0 ) ){
topB--;
if(b.data[topB] == '1'){
y = 1;
}else{
y = 0;
}
}else{
y = 0;
}
sum = x + y + carry;
if (sum == 2 || sum == 3){
carry = 1;
}else{
carry = 0;
}
if (sum == 1 || sum == 3) {
c = '1';
}else{
c = '0';
}
if(!push(&output , c)){
clearStack(&a);
clearStack(&b);
clearStack(&output);
printf("alloc error");
return 0;
}
}
if (carry == 1) {
if(!push(&output , '1')){
clearStack(&a);
clearStack(&b);
clearStack(&output);
printf("alloc error");
return 0;
}
}
clearStack(&a);
for (i=0; i < output.size; i++){
push(&a , output.data[i]);
}
clearStack(&b);
clearStack(&output);
} /*end of EOF while*/
for (i=a.size - 1; i >= 0; i--){
if(a.data[i] == '1' || start){
start=1;
printf("%c", a.data[i]);
}
}
printf("\n");
clearStack(&a);
//clearStack(&b);
//clearStack(&output);
return 0;
}
