/// <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 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);
}