Add Question 140-151.
All passed OJ test cases.
Revert "Add Question 140-151."

This reverts commit 4b4804f46c1d6341faa6285d1883e638808ab702.
Revert "Revert "Add Question 140-151.""

This reverts commit f1d04078723bb9bb48d40358079d2203736d877f.