A12396. Regular Bracket Sequence
编程题
普及/提高-
知识点
题目描述
A string is called bracket sequence if it does not contain any characters other than "(" and ")". A bracket sequence is called regular if it it is possible to obtain correct arithmetic expression by inserting characters "+" and "1" into this sequence. For example, "", "(())" and "()()" are regular bracket sequences; "))" and ")((" are bracket sequences (but not regular ones), and "(a)" and "(1)+(1)" are not bracket sequences at all.
You have a number of strings; each string is a bracket sequence of length $2$ . So, overall you have $cnt_1$ strings "((", $cnt_2$ strings "()", $cnt_3$ strings ")(" and $cnt_4$ strings "))". You want to write all these strings in some order, one after another; after that, you will get a long bracket sequence of length $2(cnt_1 + cnt_2 + cnt_3 + cnt_4)$ . You wonder: is it possible to choose some order of the strings you have such that you will get a regular bracket sequence? Note that you may not remove any characters or strings, and you may not add anything either.
You have a number of strings; each string is a bracket sequence of length $2$ . So, overall you have $cnt_1$ strings "((", $cnt_2$ strings "()", $cnt_3$ strings ")(" and $cnt_4$ strings "))". You want to write all these strings in some order, one after another; after that, you will get a long bracket sequence of length $2(cnt_1 + cnt_2 + cnt_3 + cnt_4)$ . You wonder: is it possible to choose some order of the strings you have such that you will get a regular bracket sequence? Note that you may not remove any characters or strings, and you may not add anything either.
输入格式
The input consists of four lines, $i$ -th of them contains one integer $cnt_i$ ( $0 \le cnt_i \le 10^9$ ).
输出格式
Print one integer: $1$ if it is possible to form a regular bracket sequence by choosing the correct order of the given strings, $0$ otherwise.
输入输出样例
输入 #1
3 1 4 3
输出 #1
1
输入 #2
0 0 0 0
输出 #2
1
输入 #3
1 2 3 4
输出 #3
0
说明/提示
In the first example it is possible to construct a string "(())()(()((()()()())))", which is a regular bracket sequence.
In the second example it is possible to construct a string "", which is a regular bracket sequence.
In the second example it is possible to construct a string "", which is a regular bracket sequence.