add 939

Author: luliyucoordinate

README.md

@@ -199,4 +199,5 @@ LeetCode
 |0936|[Stamping The Sequence](https://leetcode.com/problems/stamping-the-sequence/) | c | [c++](./src/0936-Stamping-The-Sequence/0936.cpp) |[python](./src/0936-Stamping-The-Sequence/0936.py)|||Hard|
 |0937|[Reorder Log Files](https://leetcode.com/problems/reorder-log-files/) | c | [c++](./src/0937-Reorder-Log-Files/0937.cpp) |[python](./src/0937-Reorder-Log-Files/0937.py)|||Easy|
 |0938|[Range Sum of BST](https://leetcode.com/problems/range-sum-of-bst/) | c | [c++](./src/0938-Range-Sum-of-BST/0938.cpp) |[python](./src/0938-Range-Sum-of-BST/0938.py)|||Medium|
-|0939|[Minimum Area Rectangle](https://leetcode.com/problems/minimum-area-rectangle/) | c | [c++](./src/0939-Minimum-Area-Rectangle/0939.cpp) |[python](./src/0939-Minimum-Area-Rectangle/0939.py)|||Medium|
+|0939|[Minimum Area Rectangle](https://leetcode.com/problems/minimum-area-rectangle/) | c | [c++](./src/0939-Minimum-Area-Rectangle/0939.cpp) |[python](./src/0939-Minimum-Area-Rectangle/0939.py)|||Medium|
+|0940|[Distinct Subsequences II](https://leetcode.com/problems/distinct-subsequences-ii/) | c | [c++](./src/0940-Distinct-Subsequences-II/0940.cpp) |[python](./src/0940-Distinct-Subsequences-II/0940.py)|||Hard|

src/0939-Minimum-Area-Rectangle/0939.cpp

@@ -0,0 +1,40 @@
+#include <iostream>
+#include <vector>
+#include <unordered_map>
+#include <set>
+#include <algorithm>
+using namespace std;
+
+static int x = []() {std::ios::sync_with_stdio(false); cin.tie(0); return 0; }();
+class Solution 
+{
+public:
+    int minAreaRect(vector<vector<int>>& points) 
+    {
+        int result = INT_MAX;
+        unordered_map<int, set<int>> columns;
+        for (auto point : points) columns[point[0]].insert(point[1]);
+        for (auto x1 = columns.begin(); x1 != columns.end(); ++x1) 
+        {
+            if (x1->second.size() < 2) continue;
+            for (auto x2 = next(x1); x2 != columns.end(); ++x2) 
+            {
+                if (x2->second.size() < 2) continue;
+                vector<int> y;
+                set_intersection(begin(x1->second), end(x1->second),
+                    begin(x2->second), end(x2->second), inserter(y, y.begin()));
+                for (unsigned int i = 1; i < y.size(); ++i)
+                    result = min(result, abs(x2->first - x1->first) * (y[i] - y[i - 1]));
+            }
+        }
+        return result == INT_MAX ? 0 : result;
+    }
+};
+
+
+int main()
+{
+    vector<vector<int>> points = {{1,1},{1,3},{3,1},{3,3},{4,1},{4,3}};
+    cout << Solution().minAreaRect(points);
+    return 0;
+}

src/0939-Minimum-Area-Rectangle/0939.py

@@ -0,0 +1,32 @@
+from collections import defaultdict
+class Solution:
+    def minAreaRect(self, points):
+        """
+        :type points: List[List[int]]
+        :rtype: int
+        """
+        n = len(points)
+        nx = len(set(x for x, y in points))
+        ny = len(set(y for x, y in points))
+        if nx == n or ny == n:
+            return 0
+        columns = defaultdict(list)
+        for x, y in points:
+            columns[x].append(y)
+
+        seen, result = {}, float('inf')
+
+        for x2 in sorted(columns):
+            column = columns[x2]
+            column.sort()
+            for j, y2 in enumerate(column):
+                for i in range(j):
+                    y1 = column[i]
+                    if (y1, y2) in seen:
+                        result = min(result, (x2 - seen[y1,y2]) * (y2 - y1))
+                    seen[y1, y2] = x2
+        return result if result != float('inf') else 0
+        
+if __name__ == "__main__":
+    points = [[1,1],[1,3],[3,1],[3,3],[4,1],[4,3]]
+    print(Solution().minAreaRect(points))