Re: ((一))

看板Marginalman作者ILoveElsa (酷拉皮卡買醬油)時間8年前 (2017/03/03 01:24)推噓1(2推 1噓 9→)

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In this problem we consider expressions containing brackets that are properly nested. These expressionsare obtained by juxtaposition of properly netsted expressions in a pair of matching brackets, the leftone an opening and the right one a closing bracket. ( a + $ ( b = ) ( a ) ) is properly nested ( a + $ ) b = ) ( a ( ) is not In this problem we have several pairs of brackets, so we have to impose a second condition on the expression: the matching brackets should be of the same kind. Consequently ‘(())’ is OK, but ‘([))’ is not. The pairs of brackets are: ( ) [ ] { } < > (* *) The two characters ‘(*’ should be interpreted as one symbol, not as an opening bracket ‘(’ followed immediately by an asterisk, and similarly for ‘*)’. The combination ‘(*)’ should be interpreted as ‘(*’followed by ‘)'. Write a program that checks wheter expressions are properly nested. If the expression is not properly nested your program should determine the position of the off ending bracket, that is the length of the shortest prefi x of the expression that can not be extended to a properly nested expression. Don’t forget ‘(*’ counts as one, as does ‘*)’. The characters that are not brackets also count as one. Input The input is a text-file. Each line contains an expression to be checked followed by and end-of-line marker. No line contains more than 3000 characters. The input ends with a standard end-of-fi le marker. Output The output is a textfi le. Each line contains the result of the check of the corresponding inputline, that is ‘YES’ (in upper case), if the expression is OK, and (if it is not OK) ‘NO’ followed by a space and the position of the error. Sample Input (*a++(*) (*a{+}*) Sample Output NO 6 YES -- 我老婆1 http://i.imgur.com/qcvvvGh.png