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;
using System.Collections.Generic;
using System.Linq;


namespace AtCoder
{
    partial class Program
    {
		static int ReadInt()
        {
            return int.Parse(Console.ReadLine());
        }
        static long ReadLong()
        {
            return long.Parse(Console.ReadLine());
        }
		static int[] ReadIntArray()
        {
            return Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
        }
        static long[] ReadLongArray()
        {
            return Console.ReadLine().Split(' ').Select(long.Parse).ToArray();
        }
		
        public static int[] ZAlgotithm(string s)
        {
            var len = s.Length;

            var a = new int[len];
            a[0] = len;
            var i = 1;
            var j = 0;
            while (i < len)
            {
                while (i + j < len && s[j] == s[i + j]) j++;
                a[i] = j;

                if (j == 0)
                {
                    i++;
                    continue;
                }

                var k = 1;
                while (i + k < len && k + a[k] < j)
                {
                    a[i + k] = a[k];
                    k++;
                }
                i += k;
                j -= k;
            }

            return a;
        }
        public class MaxHeap<T> : IEnumerable<T>
        {
            private List<T> _list;
            private Comparer<T> _comp;

            public MaxHeap() : this(0) { }
            public MaxHeap(int capacity, Comparison<T> comp=null)
            {
                _list = new List<T>(capacity);

                if (comp == null)
                {
                    _comp = Comparer<T>.Default;
                }
                else
                {
                    _comp = Comparer<T>.Create(comp);
                }
            }
            
            public void Push(T elem)
            {
                Upheap(elem);
            }

            public T Pop()
            {
                return Downheap();
            }

            public T Peek()
            {
                return _list[0];
            }

            
            private void Swap(int i, int j)
            {
                var a = _list[j];
                _list[j] = _list[i];
                _list[i] = a;
            }

            private void Upheap(T elem)
            {
                _list.Add(elem);
                var i = _list.Count - 1;

                while (true)
                {
                    if (i == 0) return;
                    var j = (i - 1) / 2;

                    var e = _list[i];
                    var p = _list[j];

                    var c = _comp.Compare(e, p);
                    if (c > 0)
                    {
                        Swap(i, j);
                        i = j;
                        continue;
                    }
                    else
                    {
                        break;
                    }
                }
            }

            private T Downheap()
            {
                var result = _list[0];

                var last = _list.Count - 1;
                Swap(0, last);
                _list.RemoveAt(last);
                if (_list.Count == 0) return result;

                var i = 0;
                while (true)
                {
                    if (i == _list.Count - 1) return result;
                    var p = _list[i];

                    var j = i * 2 + 1;
                    if (j >= _list.Count) return result;

                    if(j+1 < _list.Count && _comp.Compare(_list[j], _list[j+1]) < 0)
                    {
                        j++;
                    }

                    if (_comp.Compare(_list[i], _list[j]) < 0)
                    {
                        Swap(i, j);
                        i = j;
                    }
                    else
                    {
                        return result;
                    }
                }
            }

            public IEnumerator<T> GetEnumerator()
            {
                return _list.GetEnumerator();
            }

            IEnumerator IEnumerable.GetEnumerator()
            {
                return GetEnumerator();
            }
        }
        public class PriorityQueue<T> where T : IComparable
        {
            private IComparer<T> _comparer = null;
            private int _type = 0;

            private T[] _heap;
            private int _sz = 0;

            private int _count = 0;

            /// <summary>
            /// Priority Queue with custom comparer
            /// </summary>
            public PriorityQueue(int maxSize, IComparer<T> comparer)
            {
                _heap = new T[maxSize];
                _comparer = comparer;
            }

            /// <summary>
            /// Priority queue
            /// </summary>
            /// <param name="maxSize">max size</param>
            /// <param name="type">0: asc, 1:desc</param>
            public PriorityQueue(int maxSize, int type = 0)
            {
                _heap = new T[maxSize];
                _type = type;
            }

            private int Compare(T x, T y)
            {
                if (_comparer != null) return _comparer.Compare(x, y);
                return _type == 0 ? x.CompareTo(y) : y.CompareTo(x);
            }

            public void Push(T x)
            {
                _count++;

                //node number
                var i = _sz++;

                while (i > 0)
                {
                    //parent node number
                    var p = (i - 1) / 2;

                    if (Compare(_heap[p], x) <= 0) break;

                    _heap[i] = _heap[p];
                    i = p;
                }

                _heap[i] = x;
            }

            public T Pop()
            {
                _count--;

                T ret = _heap[0];
                T x = _heap[--_sz];

                int i = 0;
                while (i * 2 + 1 < _sz)
                {
                    //children
                    int a = i * 2 + 1;
                    int b = i * 2 + 2;

                    if (b < _sz && Compare(_heap[b], _heap[a]) < 0) a = b;

                    if (Compare(_heap[a], x) >= 0) break;

                    _heap[i] = _heap[a];
                    i = a;
                }

                _heap[i] = x;

                return ret;
            }

            public int Count()
            {
                return _count;
            }

            public T Peek()
            {
                return _heap[0];
            }

            public bool Contains(T x)
            {
                for (int i = 0; i < _sz; i++) if (x.Equals(_heap[i])) return true;
                return false;
            }

            public void Clear()
            {
                while (this.Count() > 0) this.Pop();
            }

            public IEnumerator<T> GetEnumerator()
            {
                var ret = new List<T>();

                while (this.Count() > 0)
                {
                    ret.Add(this.Pop());
                }

                foreach (var r in ret)
                {
                    this.Push(r);
                    yield return r;
                }
            }

            public T[] ToArray()
            {
                T[] array = new T[_sz];
                int i = 0;

                foreach (var r in this)
                {
                    array[i++] = r;
                }

                return array;
            }
        }
        class InputLine
        {
            private string[] _inputs;
            private int _index = 0;

            InputLine(string input)
            {
                _inputs = input.Split();
                _index = 0;
            }

            public static InputLine Read()
            {
                return new InputLine(Console.ReadLine());
            }

            public int NextInt()
            {
                return int.Parse(_inputs[_index++]);
            }
            public long NextLong()
            {
                return long.Parse(_inputs[_index++]);
            }
            public double NextDouble()
            {
                return double.Parse(_inputs[_index++]);
            }
        }
        static void Main(string[] args)
        {
			//↓

            var inputs = InputLine.Read();
            var w = inputs.NextDouble();
            var h = inputs.NextDouble();
            var x = inputs.NextDouble();
            var y = inputs.NextDouble();

            var isCenter = x == w / 2 && y == h / 2;

            Console.WriteLine(w * h / 2 + " " + (isCenter ? "1" : "0"));


			//↑
        }

	}
}