public int Calculate(string str)
{
char[] ch = str.ToCharArray();
int value = 0;
LBStack <int> st = new LBStack <int>();
foreach (char c in ch)
{
if (c == '+' || c == '-' || c == '*' || c == '/')
{
int c1 = st.Pop();
int c2 = st.Pop();
switch (c)
{
case '+': value = c2 + c1; break;
case '-': value = c2 - c1; break;
case '*': value = c2 * c1; break;
case '/': value = c2 / c1; break;
default: break;
}
st.Push(value);
}
else
{
st.Push(Convert.ToInt32(c.ToString()));
}
}
return(value);
}
public IDictionary <int, int> GetNextGreaterElement()
{
LBStack <int> st = new LBStack <int>();
foreach (int i in items)
{
st.Push(i);
}
while (!st.IsEmpty())
{
int item = st.Peek();
if (st.top == 0 || st.top == items.Length - 1)
{
st.Pop();
data.Add(item, -1);
}
else
{
st.Pop();
data.Add(item, max);
}
max = item < max ? max : item;
}
return(data);
}
public static bool Validate(string str)
{
LBStack <char> st = new LBStack <char>();
map.Add('}', '{');
map.Add(')', '(');
map.Add(']', '[');
char[] ch = str.ToCharArray();
foreach (char c in ch)
{
string s = c.ToString();
switch (s)
{
case "{":
case "(":
case "[": st.Push(c); break;
case "}":
case ")":
case "]":
string popped2 = st.Pop().ToString();
if (map[c].ToString() != popped2)
{
return(false);
}
break;
default: break;
}
}
return(st.IsEmpty());
}
public int GetMaxWithStack()
{
int i = 0;
LBStack <int> st = new LBStack <int>();
while (i < items.Length)
{
if (items[i] > items[st.Peek()] || st.IsEmpty())
{
st.Push(i);
}
else
{
while (!st.IsEmpty() && items[i] <= items[st.Peek()])
{
calculateArea(items, st, i);
}
st.Push(i);
}
i++;
}
while (!st.IsEmpty())
{
calculateArea(items, st, i);
}
return(max);
}
private void calculateArea(int[] items, LBStack <int> st, int index)
{
int pop_index = st.Pop();
int lower_bound = st.IsEmpty() ? -1 : st.Peek();
int area = items[pop_index] * ((index - 1) - lower_bound);
UpdateArea(area);
}
