摘要：
Two bored soldiers are playing card war. Their card deck consists of exactlyncards, numbered from1ton,all values are different. They divide cards betw... 阅读全文
摘要：
You are given a string consisting of parentheses()and[]. A string of this type is said to becorrect:(a)if it is the empty string(b)if A and B are corr... 阅读全文