Problem saadfareed#84 Largest Rectangle In Histogram (saadfareed#76)

C++/largest-rectangle-in-histogram.cpp

@@ -0,0 +1,36 @@
+// Name: Sumit Chakraborty
+
+// Username: chakraborty9569
+
+class Solution {
+public:
+    int largestRectangleArea(vector<int>& heights) {
+        stack<int> s;
+        int max_area=0;
+        int tp;
+        int area_with_tp;
+        int i=0;
+        while(i<heights.size())
+        {
+            if(s.empty()||heights[s.top()]<=heights[i])
+                s.push(i++);
+            else
+            {
+                tp=s.top();
+                s.pop();
+                area_with_tp=heights[tp]*(s.empty()? i : i-s.top()-1);
+                if(max_area<area_with_tp)
+                    max_area=area_with_tp;
+            }
+        }
+        while(!s.empty())
+        {
+            tp=s.top();
+            s.pop();
+            area_with_tp=heights[tp]*(s.empty()? i : i-s.top()-1);
+            if(max_area<area_with_tp)
+                max_area=area_with_tp;
+        }
+        return max_area;
+    }
+};