usaa20/cv3/program.c

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

#define STACK_SIZE 100

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

void push(struct stack* stack,float values){
    assert(stack->size < STACK_SIZE);
    stack->values[stack->size] = values;
    stack->size += 1;
}

float pop(struct stack *stack){
    assert(stack->size > 0);
    float values = stack->values[stack->size-1]; 
    stack->size -= 1; 
    return values; 
}
void print_stack(struct stack *stack){
    int i;
    int len = stack->size - 1;
    for(i = 0; i < len; i++){
        printf("%0.2f ", stack->values[i]);
    }
    if(stack->size != 0){
        printf("%0.2f ", stack->values[i]);
    }
    printf("\n");

}


int main() {
    struct stack mystack;
    memset(&mystack, 0, sizeof(struct stack));
    int i = 0;
    float z;
    for(i = 0; i < 10000; i++){
        char line[10];
        char *x = fgets(line, 10, stdin);
        float r = 0;
         
        if(!isdigit(line[0]) && line[0] != '+' && line[0] != '*' && line[0] != '/' && line[0] != '-'){
            printf("no input");
            return 0;
        }       
        
        if(line[0] == '+'){
            r = pop(&mystack) + pop(&mystack); 
        }
        else if(line[0] == '-'){
            z = pop(&mystack);
            r = pop(&mystack) - z;
        }
        else if(line[0] == '*'){
            r = pop(&mystack) * pop(&mystack);
        }
        else if(line[0] == '/'){
            z = pop(&mystack);
            if(z != 0.0){
                r = pop(&mystack) / z;
            }
        }

        else {
            r = strtof(line,&x);
        }      
        
        push(&mystack,r);
        print_stack(&mystack);
            
    }



    return 0;
}