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Author: kedebug

LargestRectangleinHistogram/LargestRectangleinHistogram.cpp

@@ -0,0 +1,35 @@
+class Solution {
+public:
+    int largestRectangleArea(vector<int>& height) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        
+        int n = height.size();
+        int width[n];
+        stack<int> minHeight;
+        
+        for (int i = 0; i < n; i++) {
+            while (!minHeight.empty() && height[i] <= height[minHeight.top()])
+                minHeight.pop();
+            int left = minHeight.empty() ? -1 : minHeight.top();
+            width[i] = i - left - 1;
+            minHeight.push(i);
+        }
+        
+        while (!minHeight.empty())
+            minHeight.pop();
+            
+        for (int i = n - 1; i >= 0; i--) {
+            while (!minHeight.empty() && height[i] <= height[minHeight.top()])
+                minHeight.pop();
+            int right = minHeight.empty() ? n : minHeight.top();
+            width[i] += right - i - 1;
+            minHeight.push(i);
+        }
+        
+        int result = 0;
+        for (int i = 0; i < n; i++) 
+            result = max(result, height[i] * (width[i] + 1));
+        return result;
+    }
+};