Trung Tố Sang Hậu Tố ( BQT CODER )

#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
using namespace std;
#define MAX 1000
struct stack {
	int top;
	char data[MAX];
};
void init(stack& s) {
	s.top = 0;
}
int isEmpty(stack s) {
	return (s.top == 0);
}
int isFull(stack s) {
	return (s.top == MAX);
}
void push(stack& s, char x) {
	if (!isFull(s)) {
		s.data[s.top] = x;
		s.top++;
	}
}
char top(stack s) {
	return s.data[s.top - 1];
}
char pop(stack& s) {
	if (!isEmpty(s)) {
		s.top--;
		return s.data[s.top];
	}
}
struct queue {
	int front, rear;
	char data[MAX];
	int n;
};
void initQueue(queue& q) {
	q.front = 0;
	q.rear = -1;
	q.n = 0;
}
bool isFullQueue(queue q) {
	return (q.n == MAX);
}
bool enQueue(queue& q, char x) {
	if (isFullQueue(q)) {
		return false;
	}
	q.rear = (q.rear + 1) % MAX;
	q.data[q.rear] = x;
	q.n++;
	return true;
}
bool isNumber(char c) {
	return c >= '0' && c <= '9';
}
bool isBest(char x, char y) {
	if (x == '(') {
		return false;
	}
	if (x == '*' || x == '/') {
		return true;
	}
	if (x == '+' || x == '-') {
		if (y == '*' || y == '/') {
			return false;
		}
		return true;
	}
}
int Precedence(char x)
{
	if (x == '(')
		return 0;
	if (x == '+' || x == '-')
		return 1;
	if (x == '*' || x == '/' || x == '%')
		return 2;

	return 3;
}
void infixToPostfix(char p[], queue& q) {
	char x;
	stack s;
	init(s);
	for (int i = 0; i < strlen(p); i++) {
		if (p[i] == '(') {
			push(s, p[i]);
		}
		else if (isNumber(p[i])) {
			enQueue(q, p[i]);
		}
		else if (p[i] == ')') {
			do {
				x = pop(s);
				if (x != '(') {
					enQueue(q, x);
				}
			} while (x != '(');
		}
		else {
			x = top(s);
			while (isBest(x,p[i])) {
				x = pop(s);
				enQueue(q, x);
				x = top(s);
			}
			push(s, p[i]);
		}
	}
	while (!isEmpty(s)) {
		x = pop(s);
		enQueue(q, x);
	}
}
void Output(queue q) {
	for (int i = q.front; i <= q.rear; i++) {
		cout << q.data[i];
	}
}
void main() {
	queue q;
	initQueue(q);
	char p[] = "3+4";
	infixToPostfix(p, q);
	Output(q);
}