package question;

import java.util.ArrayDeque;
import java.util.Deque;
import java.util.LinkedList;
import java.util.Stack;
import java.util.concurrent.ArrayBlockingQueue;

/**
 * @author Roderland
 * @since 1.0
 */
public class Question227 {
 public static void main(String[] args) {
 System.out.println(new Question227().calculate("1*2-3/4+5*6-7*8+9/10"));
 }
 public int calculate(String s) {
 char[] chars = s.toCharArray();
 Deque<Entity> stack = new LinkedList<>();
 for (char c : chars) {
 if (c==' ') continue;
 if (c=='+') stack.addLast(new Entity(1, 0));
 else if (c=='-') stack.addLast(new Entity(2, 0));
 else if (c=='*') stack.addLast(new Entity(3, 0));
 else if (c=='/') stack.addLast(new Entity(4, 0));
 else {
 if (stack.isEmpty()) {
 stack.addLast(new Entity(0, c-'0'));
 } else {
 Entity peek = stack.peekLast();
 if (peek.type==0) {
 int value = stack.pollLast().value;
 if (value>=0) stack.addLast(new Entity(0, peek.value*10+(c-'0')));
 else stack.addLast(new Entity(0, peek.value*10-(c-'0')));
 } else if (peek.type==1) {
 stack.addLast(new Entity(0, c-'0'));
 } else if (peek.type==2) {
 stack.pollLast();
 stack.addLast(new Entity(0, -(c-'0')));
 } else if (peek.type==3) {
 stack.addLast(new Entity(0, c-'0'));
// stack.pop();
// stack.push(new Entity(0, stack.pop().value*(c-'0')));
 } else if (peek.type==4) {
 stack.addLast(new Entity(0, c-'0'));
// stack.pop();
// stack.push(new Entity(0, stack.pop().value/(c-'0')));
 }
 }
 }
 }

 Deque<Entity> reStack = new LinkedList<>();
 while (!stack.isEmpty()) {
 Entity entity = stack.removeFirst();
 if (entity.type==3) {
 reStack.addLast(new Entity(0, reStack.removeLast().value*stack.removeFirst().value));
 } else if (entity.type==4) {
 reStack.addLast(new Entity(0, reStack.removeLast().value/stack.removeFirst().value));
 } else {
 reStack.addLast(entity);
 }
 }
 int res = 0;
 while (!reStack.isEmpty()) {
 Entity entity = reStack.removeFirst();
 if (entity.type==0) res+=entity.value;
 }
 return res;
 }

 static class Entity {
 // 数字:0;加号:1;减号:2;乘号:3;除号:4;
 int type;
 int value;

 public Entity(int type, int value) {
 this.type = type;
 this.value = value;
 }
 }
}