1. Remove duplicate characters and press ASCII ordering: enter a string ends with a carriage return (less than 80 characters), removed after repeating characters, according to the characters of the ASCII order from small to large, sorted output
2. Assuming that the students' basic information, including student id, name, math scores, most need to deal with data of 50 students, input n student achievement information, according to the students' math scores from high to low output of their information,