Evaluate Reverse Polish Notation — Operand Stack

# Python
def evalRPN(tokens):
    stack = []
    ops = {'+': lambda a,b: a+b, '-': lambda a,b: a-b,
           '*': lambda a,b: a*b, '/': lambda a,b: int(a/b)}
    for t in tokens:
        if t in ops:
            b, a = stack.pop(), stack.pop()
            stack.append(ops[t](a, b))
        else:
            stack.append(int(t))
    return stack[0]

// Java
public int evalRPN(String[] tokens) {
    Deque<Integer> stack = new ArrayDeque<>();
    for (String t : tokens) {
        if ("+-*/".contains(t)) {
            int b = stack.pop(), a = stack.pop();
            switch(t) {
                case "+": stack.push(a+b); break;
                case "-": stack.push(a-b); break;
                case "*": stack.push(a*b); break;
                case "/": stack.push(a/b); break;
            }
        } else stack.push(Integer.parseInt(t));
    }
    return stack.pop();
}