题库练习 Regular Bracket Sequence
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A12396 | Regular Bracket Sequence

时间限制1s
内存限制256MB
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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.

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
C++ 编辑器
输入
输出