Add soulution for problem 084 Largest Rectangle in Histogram

C++/084_Largest_Rectangle_in_Histogram.cpp

@@ -0,0 +1,51 @@
+//84. Largest Rectangle in Histogram
+/*
+ *Given n non-negative integers representing the histogram's bar height where the width of each bar is 1, find the area of largest rectangle in the histogram.
+ *
+ *
+ *Above is a histogram where width of each bar is 1, given height = [2,1,5,6,2,3].
+ *
+ *
+ *The largest rectangle is shown in the shaded area, which has area = 10 unit.
+ *
+ *For example,
+ *Given heights = [2,1,5,6,2,3],
+ *return 10.
+ *
+ *Tag: Array, Stack
+ *
+ *Author: Linsen Wu
+ */
+
+#include "stdafx.h"
+#include <vector>
+#include <stack>
+
+using namespace std;
+
+class Solution {
+public:
+    int largestRectangleArea(vector<int>& heights) {
+        stack<int> MtSt;  
+        heights.push_back(0);  
+        int sum = 0;  
+        for (int i = 0; i < heights.size(); i++) {  
+            if (MtSt.empty() || heights[i] > heights[MtSt.top()]) {
+                MtSt.push(i);
+            }
+            else {  
+                int tmp = MtSt.top();  
+                MtSt.pop();  
+                sum = max(sum, heights[tmp]*(MtSt.empty()? i : i-MtSt.top()-1));  
+                i--;  
+            }  
+        }  
+        return sum;
+    }
+};
+
+int _tmain(int argc, _TCHAR* argv[])
+{
+    return 0;
+}
+