usaa24/cv3/program.c

#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <ctype.h>
//// @ 
#define STACK_SIZE 10

struct Stack
{
   float values[STACK_SIZE];
   int size;
};

void push_stack(struct Stack* stack, float value);
float pop_stack(struct Stack* stack);
int count_stack(struct Stack* stack);


void push_stack(struct Stack* stack, float value)
{
    assert(stack->size < STACK_SIZE); 
    stack->values[stack->size] = value;
    stack->size += 1;
}
float pop_stack(struct Stack* stack)
{
    assert(stack->size > 0); 
    float value = stack->values[stack->size-1];
    stack->size -= 1;
    return value;
}
int count_stack(struct Stack* stack)
{
  return stack->size;
}

void print_stack(struct Stack* stack)
{
    for (int i=0; i<stack->size; i++)
    {
        printf("%.2f ", stack->values[i]);
    }
    printf("\n");
}


int main()
{
    struct Stack mystack;
    mystack.size=0;
    //memset(&mystack,0,sizeof(struct Stack));
    int err=0;

    char buf[505];

    do
    {        
      char* p=fgets(buf, 299, stdin);    
      if(p)
      {
          char c=buf[0];
          float op1, op2, rez;
          if(c=='+'||c=='-'||c=='/'||c=='*')  
          {
              if(count_stack(&mystack)<2)
              {
                  printf("not enough operands\n");
                  err=3;
                  break;
              }
              op2=pop_stack(&mystack);
              op1=pop_stack(&mystack);
              switch(c)
              {
                  case '+': rez=op1+op2; break;
                  case '-': rez=op1-op2; break;
                  case '/': 
                            if(c=='/' && op2==0) 
                            {
                                err=1;
                                printf("division by zero\n");  
                            }
                            else
                                rez=op1/op2;
                            break;
                  case '*': rez=op1*op2; break;
              }              
          }
          else 
          {
              if(isdigit(c))
              {
                rez=atof(buf);
              }
              else
              {
                err=1;
                printf("bad input\n");
              }
          }
          
          if(!err)
          {
             if(count_stack(&mystack)==STACK_SIZE)  
             {
                 printf("full stack\n");
                 err=4;
                 break;
             }
            push_stack(&mystack, rez); 
            print_stack(&mystack);
          }
      }  
      else break;

    }while(1);
    if(!err)
        printf("no input\n");
	return 0;
}