coding-Interview/BasicCalculatorWords.java at master · arjunmullick/coding-Interview · GitHub

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import java.io.*;

import java.util.HashMap;

import java.util.*;

import com.fasterxml.jackson.databind.ObjectMapper;

import com.fasterxml.jackson.core.JsonProcessingException;

Advance

Implement the same but with grouping.

eval("(five plus four)") == 9

eval("(one plus one) times ten") == 20

eval("five times (two plus negative one)") == 5

eval("(two plus negative four) times (ten plus one)") == -22

eval("(one plus (three plus four) times five)") == 36

eval("(one plus seven) times three plus four") == 28

eval("(one plus seven) times (three plus four)") == 56

eval("(one plus seven) times (three plus (four plus one plus (negative one)))") == 56

eval("(one plus seven) times (three plus (four plus one plus negative one))") == 56

eval("(one plus seven) times (negative three plus four)") == 8

eval("(five plus negative four) times three") == 3

eval("(five plus negative four) times (three plus four)") == 7

// Main class should be named 'Solution'

class Solution {

public static HashMap<String,Integer> numbers = new HashMap<>();

public static HashMap<String,Character> operations = new HashMap<>();

public static void initMap(){

numbers.put("zero", 0);

numbers.put("one",1);

numbers.put("two",2);

numbers.put("three", 3);

numbers.put("four", 4);

numbers.put("five",5);

numbers.put("six",6);

numbers.put("seven",7);

numbers.put("eight",8);

numbers.put("nine",9);

numbers.put("ten", 10);

operations.put("plus", '+');

operations.put("times", '*');

//operations.put("negative", '-');

}

public static int eval(String str){

if(str == null || str.length() == 0) return 0;

Stack<Integer> stack = new Stack<>();

Character op = '+';//revisit

int num = 0;

String[] arr = str.split(" ");

int n = arr.length;

boolean negative = false;

for(int i = 0 ; i < n ; i++){

String word = arr[i];

if(word.length() == 0) continue;

if(numbers.containsKey(word)){

//System.out.println(word + " " + op);

if(op == '+'){

num = numbers.get(word);

if(negative) {

stack.push(-num);

}else{

stack.push(num);

}

negative = false;//reset

}else if(op == '*'){

int prev = stack.pop();

num = prev * numbers.get(word);

if(negative) {

stack.push(-num);

}else{

stack.push(num);

}

negative = false;//reset

} else if(op == '-'){

num = -1 * numbers.get(word);

stack.push(num);

}

}else if(operations.containsKey(word)){

op = operations.get(word);

}else if(word.equals("negative")){

negative = true;

}

//System.out.println(stack);

int ans = 0;

while(stack.size() > 0){

ans = ans + stack.pop();

}

return ans;

}

public static void main(String[] args) {

System.out.println("Hello, World");

initMap();

System.out.println(eval("one plus one"));

System.out.println(eval("five plus two times negative one"));

System.out.println(eval("negative three times ten"));

System.out.println(eval("five times three plus one"));

System.out.println(eval("two times three times four"));

System.out.println(eval("two times three plus four times five"));

System.out.println(eval("two plus three times four plus five"));

System.out.println(eval("two times three times four plus five times six"));

System.out.println(eval("two times three plus four plus five plus six times seven"));

}

coding-Interview/BasicCalculatorWords.java at master · arjunmullick/coding-Interview · GitHub

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