public static bool AreParenthesisBalanced(String str)
{
MyStack <char> myStack = new SllStack <char>();
List <Char> startingParenthsis = new List <char>()
{
'[', '{', '('
};
List <Char> endingParenthsis = new List <char>()
{
']', '}', ')'
};
Dictionary <char, char> dictionary = new Dictionary <char, char>();
dictionary.Add(']', '[');
dictionary.Add('}', '{');
dictionary.Add(')', '(');
foreach (var ch in str)
{
if (startingParenthsis.Contains(ch))
{
myStack.Push(ch);
}
else if (endingParenthsis.Contains(ch))
{
if (!myStack.IsEmpty() && dictionary[ch].CompareTo(myStack.Peek()) == 0)
{
myStack.Pop();
}
else
{
return(false);
}
}
else
{
//discard other characters
}
}
//at the end nothing should be left out on stack
return(myStack.Count == 0);
}
/// <summary>
/// This prints greater element distance on left side. If no grater found, then Ith index is its span
/// </summary>
public static void PrintStockSpan(int[] arr)
{
if (arr.Length == 0)
{
return;
}
MyStack <int> myStack = new SllStack <int>();
myStack.Push(arr.Length - 1); // Pushing index, not the element
for (int i = arr.Length - 2; i >= 0; i--)
{
int currentItem = arr[i];
if (!myStack.IsEmpty())
{
int peekedItem = arr[myStack.Peek()];
while (currentItem > peekedItem) //we found greter on left for some item
{
Console.WriteLine("For item " + peekedItem + ", stock span is: " + (myStack.Peek() - i));
myStack.Pop(); //Remove that processed item
if (!myStack.IsEmpty())
{
peekedItem = arr[myStack.Peek()]; //there can be many small than current item in stack
}
else
{
break;
}
}
}
//Add current item index to stack
myStack.Push(i);
}
//Once we are done with this, all items in stack doesn't have greater on right.
while (!myStack.IsEmpty())
{
Console.WriteLine("For item " + arr[myStack.Peek()] + ", stock span last is: " + (myStack.Peek() + 1));
myStack.Pop();
}
}
public void Run()
{
ArrayStack <int> arrayStack = new ArrayStack <int>(10);
arrayStack.Push(2);
arrayStack.Push(5);
arrayStack.Push(1);
arrayStack.Push(6);
foreach (var item in arrayStack)
{
Console.WriteLine("Item:" + item);
}
Console.WriteLine("---------");
SllStack <int> sllStack = new SllStack <int>(); //no need of any capacity
sllStack.Push(2);
sllStack.Push(5);
sllStack.Push(1);
sllStack.Push(6);
foreach (var item in sllStack)
{
Console.WriteLine("Item:" + item);
}
Console.WriteLine("---------");
DllStack <int> dllStack = new DllStack <int>(); //no need of any capacity
dllStack.Push(1);
Console.WriteLine("Middle:" + dllStack.GetMiddleNodeData());
dllStack.Push(2);
Console.WriteLine("Middle:" + dllStack.GetMiddleNodeData());
dllStack.Push(3);
Console.WriteLine("Middle:" + dllStack.GetMiddleNodeData());
dllStack.Push(4);
Console.WriteLine("Middle:" + dllStack.GetMiddleNodeData());
foreach (var item in dllStack)
{
Console.WriteLine("Item:" + item);
}
Console.WriteLine("---------");
SpecialStack <int> specialStack = new SpecialStack <int>(); //no need of any capacity
specialStack.Push(2);
specialStack.Push(5);
specialStack.Push(1);
specialStack.Push(6);
while (!specialStack.IsEmpty())
{
Console.WriteLine("Item:" + specialStack.Peek() + ", min:" + specialStack.GetMin() + ", max:" + specialStack.GetMax());
specialStack.Pop();
}
Console.WriteLine("---------");
Console.WriteLine("Balanced: " + StackAlgos.AreParenthesisBalanced("[(1*2)+{5+6}"));
Console.WriteLine("---------");
StackAlgos.ReverseStackUsingStackOperationsOnly(arrayStack);
Console.WriteLine("After reverse");
foreach (var item in arrayStack)
{
Console.WriteLine("Item:" + item);
}
Console.WriteLine("---------");
StackAlgos.PrintNextGreaterElementInRightSideForAll(new int[] { 10, 4, 5, 90, 120, 80 });
Console.WriteLine("---------");
StackAlgos.PrintStockSpan(new int[] { 10, 4, 5, 90, 120, 80 });
Console.WriteLine("---------");
StackAlgos.MaxAreaRectangleFromHistogram(new int[] { 6, 2, 5, 4, 5, 1, 6 });
Console.WriteLine("---------");
int count = StackAlgos.MinNumberOfReversalNeededToMakeExpressionValid("}{{}}{{{");
Console.WriteLine("Number of reversal nedded:" + count);
Console.WriteLine("---------");
int disk = 4;
StackAlgos.TowerOfHanoi(disk);
Console.WriteLine("---------");
Console.ReadKey();
}