Struk LAB 3

// Stek.h
#pragma once
#include <iostream>
using namespace std;

class Stek {
    char* niz;
    int top;
    int numOfElements;

public:

    Stek(int n) {
        numOfElements = n;
        niz = new char[numOfElements]();
        top = -1;
    }

    void push(char ch) {
        if (top + 1 == numOfElements) {
            cout << "Stek je pun!\n";
            return;
        }
        top++;
        niz[top] = ch;
    }

    char pop() {
        if (top >= 0) {
            char vrati = niz[top];
            top--;
            return vrati;
        }
        else
            cout << "Stek je prazan!\n";
    }

    void infix2postfix(char* izraz) {
        int i = 0;
        while (izraz[i] != '\0') {
            if (izraz[i] != '+' && izraz[i] != '-' && izraz[i] != '*' && izraz[i] != '/' && izraz[i] != '^' && izraz[i] != '(' && izraz[i] != ')') {
                cout << izraz[i];
                i++;
                continue;
            }
            if (izraz[i] == '(') {
                push('(');
                i++;
                continue;
            }
            if (izraz[i] == ')') {
                char ch = pop();
                while (ch != '(') {
                    cout << ch;
                    ch = pop();
                }
                i++;
                continue;
            }
            if (izraz[i] != '+' || izraz[i] != '-' || izraz[i] != '*' || izraz[i] != '/' || izraz[i] != '^') {
                if (top < 0) {
                    push(izraz[i]);
                    i++;
                    continue;
                }
                if (!stepenOp(niz[top], izraz[i])) {
                    cout << pop();
                    while (!stepenOp(niz[top], izraz[i]) && numOfElements > 0) {
                        cout << pop();
                    }
                    push(izraz[i]);
                    i++;
                    continue;
                }
                push(izraz[i]);
            }
            i++;
        }
        while (top >= 0) {
            cout << pop();
        }
        cout << endl;
    }

private:

    bool stepenOp(char x, char y) {
        if (x == '-' || x == '+') {
            if (y == '+' || y == '-')
                return 0;
            else
                return 1;
        }
        if (x == '*' || x == '/') {
            if (y == '+' || y == '-' || y == '*' || y == '/')
                return 0;
            else
                return 1;
        }
        if (x == '^') {
            return 0;
        }
        return 1;
    }
};

// main
#pragma once
#include "stek.h"

void main() {
    char string[200];
    cout << "Napisite izraz za prebacivanje:\n";
    gets_s(string);
    Stek a(10);
    a.infix2postfix(string);
}