Problem:
Score : 300 points

Problem Statement

There is a rectangle in a coordinate plane. The coordinates of the four vertices are (0,0), (W,0), (W,H), and (0,H).
You are given a point (x,y) which is within the rectangle or on its border. We will draw a straight line passing through (x,y) to cut the rectangle into two parts. Find the maximum possible area of the part whose area is not larger than that of the other. Additionally, determine if there are multiple ways to cut the rectangle and achieve that maximum.

Constraints

1 \leq W,H \leq 10^9

0\leq x\leq W

0\leq y\leq H

All values in input are integers.

Input

Input is given from Standard Input in the following format:

W H x y

Output

Print the maximum possible area of the part whose area is not larger than that of the other, followed by 1 if there are multiple ways to cut the rectangle and achieve that maximum, and 0 otherwise.

The area printed will be judged correct when its absolute or relative error is at most 10^{-9}.

Sample Input 1

2 3 1 2

Sample Output 1

3.000000 0

The line x=1 gives the optimal cut, and no other line does.

Sample Input 2

2 2 1 1

Sample Output 2

2.000000 1

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using static System.Math;
using System.Linq;
using System.Text;
 
class DandA {
    static void Main(string[] args) {
        long[] whxy = ReadLineLongArray();
        decimal rtn1 = (decimal)(whxy[0] * whxy[1]) / 2;
        int rtn2 = whxy[0] == (2 * whxy[2]) && whxy[1] == (2 * whxy[3]) ? 1 : 0;
        Console.WriteLine(rtn1 + " " + rtn2);
    }
 
    static string Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ";
    static string[] strAry = new string[] {"L", "R", "U", "D"};
    static int[] intArray = new int[10];
    static List<int> intList = new List<int>();
    static Dictionary<string, int> myTable = new Dictionary<string, int>();
    static HashSet<int>[] rtnArrAb = null;
    static HashSet<int>[] rtnArrCd = null;
  
    static private string ReadLineStr() {return Console.ReadLine();}
    static private int ReadLineInt() {return int.Parse(Console.ReadLine());}
    static private long ReadLineLong() {return long.Parse(Console.ReadLine());}
    static private double ReadLineDouble() {return double.Parse(Console.ReadLine());}
    static private string[] ReadLineStrArray() {return Console.ReadLine().Trim().Split();}
    static private int[] ReadLineIntArray() {return Console.ReadLine().Trim().Split().Select(a => int.Parse(a)).ToArray();}
    static private long[] ReadLineLongArray() {return Console.ReadLine().Trim().Split().Select(a => long.Parse(a)).ToArray();}
    static private double[] ReadLineDoubleArray() {return Console.ReadLine().Trim().Split().Select(a => double.Parse(a)).ToArray();}
    static private decimal[] ReadLineDecimalArray() {return Console.ReadLine().Trim().Split().Select(a => decimal.Parse(a)).ToArray();}
    static private List<int> ReadLineIntList() {return Console.ReadLine().Trim().Split().Select(a => int.Parse(a)).ToList();}
    static private List<long> ReadLineLongList() {return Console.ReadLine().Trim().Split().Select(a => long.Parse(a)).ToList();}
    static private string[][] ReadMLineStrArray(int arg) { return new int[arg].Select(_ => Console.ReadLine().Split()).ToArray();}
    static private int[][] ReadMLineIntArray(int arg) { return new int[arg].Select(_ => Console.ReadLine().Split().Select(int.Parse).ToArray()).ToArray();}
 
    static private bool IsPrime(int num) {
        if (num < 2) return false;
        if (num == 2) return true;
        else if (num % 2 == 0) return false;
        double sqrtNum = Math.Sqrt(num);
        for (int i = 3; i <= sqrtNum; i += 2) {
            if (num % i == 0) return false;
        }
        return true;
    }
  
    static private string IntToNString(int x, int n) {
        var nstring = "";
        var numbers = new string[] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
        int r = 1;
        int q = x;
        while (q > 0) {
            r = q % n;
            nstring += numbers[r];
            q = q / n;
        }
        return string.Join("",nstring.Reverse());
    }
    static private long Gcd(long m,long n){
        long temp;
        while(m % n != 0){
            temp = n;
            n = m % n;
            m = temp;
        }
        return n;
    }
}