Parity Game
题目描述
You are fishing with polar bears Alice and Bob. While waiting for the fish to bite, the polar bears get bored. They come up with a game. First Alice and Bob each writes a 01-string (strings that only contain character "0" and "1") a and b. Then you try to turn a into b using two types of operations:
- Write parity(a) to the end of a. For example,
. - Remove the first character of a. For example,
. You cannot perform this operation if a is empty.
You can use as many operations as you want. The problem is, is it possible to turn a into b?
The parity of a 01-string is 1 if there is an odd number of "1"s in the string, and 0 otherwise.
The first line contains the string a and the second line contains the string b (1≤|a|,|b|≤1000). Both strings contain only the characters "0" and "1". Here |x| denotes the length of the string x.
Print "YES" (without quotes) if it is possible to turn a into b, and "NO" (without quotes) otherwise.
01011
0110
YES
0011
1110
NO
In the first sample, the steps are as follows: 01011→1011→011→0110
题目来源：fps-www.educg.net-codeforce-1-2833.xml.zip；FPS 共享题包，题包内第 2103 题。保留原作者与原赛事署名。