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

#define STACK_SIZE 10


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


void init_stack(struct stack* s) {
    memset(s, 0, sizeof(struct stack));
}


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


float pop_stack(struct stack* s) {
    assert(s->size > 0); 
    s->size -= 1;
    return s->values[s->size];
}


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


void process_operation(struct stack* s, const char* operation) {
    float b = pop_stack(s);
    float a = pop_stack(s);
    if (strcmp(operation, "+") == 0) {
        push_stack(s, a + b);
    } else if (strcmp(operation, "-") == 0) {
        push_stack(s, a - b);
    } else if (strcmp(operation, "*") == 0) {
        push_stack(s, a * b);
    } else if (strcmp(operation, "/") == 0) {
        if (b == 0) {
            printf("Chyba: Delenie nulou.\n");
            exit(1); 
        }
        push_stack(s, a / b);
    }
}

int main() {
    struct stack mystack;
    init_stack(&mystack); 

    char input[256];
    int has_input = 0; 

    printf("Poľská kalkulačka\n");
    while (1) {
        
        printf("Zadajte číslo alebo operáciu (+, -, *, /): ");
        if (!fgets(input, sizeof(input), stdin)) {
            break; 
        }

        
        input[strcspn(input, "\n")] = 0;

        
        char* endptr;
        float value = strtof(input, &endptr);
        if (endptr != input) { 
            push_stack(&mystack, value);
            has_input = 1; 
            print_stack(&mystack);
            continue; 
        }

        
        if (strcmp(input, "+") == 0 || strcmp(input, "-") == 0 || 
            strcmp(input, "*") == 0 || strcmp(input, "/") == 0) {
            if (mystack.size < 2) {
                printf("Chyba: Nedostatok hodnôt v zásobníku.\n");
                break; 
            }
            process_operation(&mystack, input);
            print_stack(&mystack);
        } else {
            printf("Chyba: Neplatný vstup.\n");
            break; 
        }
    }

   
    if (has_input) {
        printf("no input\n");
    } else {
        printf("no input\n");
    }

    return 0;
}