Simple Expression

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Scanner;


public class SimpleExpression {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        StringBuilder line = new StringBuilder(sc.nextLine());
        for (int i = 0; i < line.length(); i++) {
            if (line.charAt(i) == ' ') {
                line = line.deleteCharAt(i);
                i--;
            }
        }
        //System.out.println(line);
        BigDecimal result = BigDecimal.ZERO, lhs, rhs;
        String expr = line.toString();
        String[] operands = expr.split("[+-]");
        ArrayList<Character> signes = new ArrayList<>();
        for (int i = 0; i < expr.length(); i++) {
            if (expr.charAt(i) == '+' || expr.charAt(i) == '-') {
                signes.add(expr.charAt(i));
            }
        }

        //System.out.println(Arrays.asList(operands));
        //System.out.println(signes);

        if (operands[0].equals("")) {
            lhs = new BigDecimal(Double.parseDouble(operands[1]));
            if (signes.get(0) == '-') {
                lhs = lhs.negate();
            }
            for (int i = 1; i < operands.length - 1; i++) {
                rhs = new BigDecimal(Double.parseDouble(operands[i + 1]));
                if (signes.get(i) == '+') {
                    result = lhs.add(rhs);
                }
                else {
                    result = lhs.subtract(rhs);
                }
                lhs = result;
            }
        }
        else {
            lhs = new BigDecimal(Double.parseDouble(operands[0]));
            for (int i = 1; i < operands.length; i++) {
                rhs = new BigDecimal(Double.parseDouble(operands[i]));
                if (signes.get(i - 1) == '+') {
                    result = lhs.add(rhs);
                }
                else {
                    result = lhs.subtract(rhs);
                }
                lhs = result;
            }
        }
        System.out.printf("%.7f%n", result);

    }

}