/// <summary>
/// Given an array of integers, return indices of the two numbers such that they add up to a specific target.
// You may assume that each input would have exactly one solution, and you may not use the same element twice.
// Example:
// Given nums = [2, 7, 11, 15], target = 9,
// Because nums[0] + nums[1] = 2 + 7 = 9,
// return [0, 1].
// </summary>
// <param name="nums"></param>
// <param name="target"></param>
// <returns></returns>
//Problem with this solution is, it won't keep the original array indices intact
public static bool CalculateTwoSumUsingSortingArray(int[] nums, int target)
{
bool result = false;
int left = 0;
int right = nums.Length - 1;
QuickSorting.QuickSort(nums, left, right);
while (left < right)
{
if (nums[left] + nums[right] == target)
{
result = true;
break;
}
else if (nums[left] + nums[right] <= target)
{
left++;
}
else
{
right--;
}
}
return(result);
}
public void TestRandomArray()
{
bool test = true;
int[] array = new int[1000];
var rand = new Random();
for (int i = 0; i < array.Length; i++)
{
array[i] = rand.Next(0, 999);
}
QuickSorting.QuickSort(array, 0, array.Length - 1);
/* полная проверка всего массива
* for (int i = 0; i < array.Length - 1; i++)
* {
* if (array[i] > array[i + 1])
* {
* test = false;
* break;
* }
* }*/
for (int i = 0; i < 10; i++)
{
var a = rand.Next(0, 998);
if (array[a] > array[a + 1])
{
test = false;
break;
}
}
Assert.IsTrue(test);
}
public void TestLitleArray()
{
bool test = true;
int[] array = new[] { 4, 8, 3 };
QuickSorting.QuickSort(array, 0, array.Length - 1);
if (array[0] > array[1] || array[1] > array[2])
{
test = false;
}
Assert.IsTrue(test);
}
public void TestEmptyArray()
{
bool test = true;
int[] array = new int[0];
QuickSorting.QuickSort(array, 0, array.Length - 1);
for (int i = 0; i < array.Length - 1; i++)
{
if (array[i] > array[i + 1])
{
test = false;
break;
}
}
Assert.IsTrue(test);
}
public void TestSameNumberArray()
{
bool test = true;
int[] array = new int [100];
for (int i = 0; i < array.Length; i++)
{
array[i] = 1;
}
QuickSorting.QuickSort(array, 0, array.Length - 1);
if (array[0] > array[array.Length - 1])
{
test = false;
}
Assert.IsTrue(test);
}
public void TestBigArray()
{
bool test = true;
int[] array = new int[150000000]; // 4гб оперативной памяти, процессор i3
var rand = new Random();
for (int i = 0; i < array.Length; i++)
{
array[i] = rand.Next(0, 1499999);
}
QuickSorting.QuickSort(array, 0, array.Length - 1);
for (int i = 0; i < array.Length - 1; i++)
{
if (array[i] > array[i + 1])
{
test = false;
break;
}
}
Assert.IsTrue(test);
}
