Codeforces Round 178 (Div. 2) B. Shaass and Bookshelf

Codeforces Round 179 (Div. 1) B. Greg and Graph

Codeforces Round 180 (Div. 1) A. Parity Game

605. Can Place Flowers

You have a long flowerbed in which some of the plots are planted, and some are not. However, flowers cannot be planted in adjacent plots.

Given an integer array flowerbed containing 0‘s and 1‘s, where 0 means empty and 1 means not empty, and an integer n, return if n new flowers can be planted in the flowerbed without violating the no-adjacent-flowers rule.

Codeforces Round 183 (Div. 1) B. Rectangle Puzzle II

Codeforces Round 184 (Div. 2) B. Continued Fractions

ABBYY Cup 3.0 G3. Good Substrings

ABBYY Cup 3.0 G2. Good Substrings

ABBYY Cup 3.0 G1. Good Substrings

Codeforces Round 190 (Div. 1) A. Ciel and Robot