Evaluate the value of an arithmetic expression in Reverse Polish Notation.
Valid operators are+,-,*,/. Each operand may be an integer or another expression.
import java.util.Stack;
public class Solution {
public int evalRPN(String[] tokens) {
Stack<Integer> stack = new Stack<Integer>();
for(String t : tokens){
switch(t){
case"+":
stack.push(stack.pop()+stack.pop());
break;
case"-":
stack.push(-stack.pop()+stack.pop());
break;
case"*":
stack.push(stack.pop()*stack.pop());
break;
case"/":
int num1 = stack.pop();
int num2 = stack.pop();
stack.push(num2/num1);
break;
default:
stack.push(Integer.parseInt(t));
}
}
return stack.pop();
}
}
