摘要： 1068 Find More Coins (30)（30 分） Eva loves to collect coins from all over the universe, including some other planets like Mars. One day she visited a u 阅读全文

摘要： The task is simple: given any positive integer N, you are supposed to count the total number of 1's in the decimal form of the integers from 1 to N. F 阅读全文

摘要： Eva is trying to make her own color stripe out of a given one. She would like to keep only her favorite colors in her favorite order by cutting off th 阅读全文