Update README.md

kamyu104 · web-flow · commit 9d523bfafeb8 · 2018-07-29T02:42:36.000+08:00
diff --git a/README.md b/README.md
@@ -504,6 +504,10 @@ I'll keep updating for full summary and better solutions. Stay tuned for updates
 836 | [Rectangle Overlap](https://leetcode.com/problems/rectangle-overlap/) | [C++](./C++/rectangle-overlap.cpp) [Python](./Python/rectangle-overlap.py) | _O(1)_ | _O(1)_ | Easy |||
 858 | [Mirror Reflection](https://leetcode.com/problems/mirror-reflection/) | [C++](./C++/mirror-reflection.cpp) [Python](./Python/mirror-reflection.py) | _O(1)_ | _O(1)_ | Medium |||
 867 | [Prime Palindrome](https://leetcode.com/problems/prime-palindrome/) | [C++](./C++/prime-palindrome.cpp) [Python](./Python/prime-palindrome.py) | _O(1)_ | _O(1)_ | Medium |||
+880 | [Random Pick with Weight](https://leetcode.com/problems/random-pick-with-weight/) | [C++](./C++/random-pick-with-weight.cpp) [Python](./Python/random-pick-with-weight.py) | ctor: _O(n)_ <br> pick: _O(logn)_ | _O(n)_ | Medium |||
+881 | [Random Flip Matrix](https://leetcode.com/problems/random-flip-matrix/) | [C++](./C++/random-flip-matrix.cpp) [Python](./Python/random-flip-matrix.py) | ctor: _O(1)_ <br> pick: _O(1)_ reset: _O(n)_ | _O(n)_ | Medium |||
+882 | [Random Point in Non-overlapping Rectangles](https://leetcode.com/problems/random-point-in-non-overlapping-rectangles/) | [C++](./C++/random-point-in-non-overlapping-rectangles.cpp) [Python](./Python/random-point-in-non-overlapping-rectangles.py) | ctor: _O(n)_ <br> pick: _O(logn)_ | _O(n)_ | Medium |||
+883 | [Generate Random Point in a Circle](https://leetcode.com/problems/generate-random-point-in-a-circle/) | [C++](./C++/generate-random-point-in-a-circle.cpp) [Python](./Python/generate-random-point-in-a-circle.py) | _O(1)_ | _O(1)_ | Medium |||
 
 ## Sort
 |  #  | Title           |  Solution       |  Time           | Space           | Difficulty    | Tag          | Note| 
