#define ll long long

#include <stdio.h>
#include <mm_malloc.h>
#include <memory.h>
#include <stdbool.h>
#include <ctype.h>

typedef struct {
    int* arrayOfIntegers;
    int size;
} stack;


stack* createStack(size_t size) {
    stack *newStack = calloc(1, sizeof(stack));
    newStack -> arrayOfIntegers = (int*)calloc(size, sizeof(int));
    newStack -> size = 0;
    return newStack;
}

//Add the element to stack                                                                  Time: O(1)
void push(stack* stack, int value) {

}

//Returns the element on the peek of stack                                                  Time: O(1)
int peek(stack* stack) {

}

//Delete the peek element from stack                                                        Time: O(1)
void pop(stack* stack) {

}


char* getLine() {

}

//Splitting expression to "Tokens" which can be numbers or symbols of operations            Time: O(length)
char** splitBySpaces(char* expression, int *quantityOfTokens) {

}


//All of the methods below are calculating an operation for two peek operands in stack      Time: O(1)
void operationAdd(stack* stack) {

}

void operationSubtract(stack* stack) {

}

void operationMultiply(stack* stack) {

}

void operationDivide(stack* stack) {

}

//Checking a token if it's a number                                                           Time: O(length)
bool isNumber(char* token) {
    for (size_t i = 0; i < strlen(token); i++) {
        if (!isdigit(token[i])) {
            return false;
        }
    }
    return true;
}

int main() {
    stack* stackOfNumbers = createStack(1000);

    char* expression = (char*)calloc(1001, sizeof(char));
    if (!expression) {
        printf("No memory?!");
        exit(1);
    } else {
        expression = getLine();
    }

    int quantityOfTokens = 0;
    char** splittedString = splitBySpaces(expression, &quantityOfTokens);

    for (int i = 0; i < quantityOfTokens; i++) {
        if (strcmp(splittedString[i], "+") == 0) {
            operationAdd(stackOfNumbers);
        } else if (strcmp(splittedString[i], "-") == 0) {
            operationSubtract(stackOfNumbers);
        } else if (strcmp(splittedString[i], "*") == 0) {
            operationMultiply(stackOfNumbers);
        } else if (strcmp(splittedString[i], "/") == 0) {
            operationDivide(stackOfNumbers);
        } else if (isNumber(splittedString[i])){
            push(stackOfNumbers, );
        } else {
            printf("bad input");
            exit(1);
        }
    }
    return 0;
}