modify hw5 and finish the format changing
modify hw5 and finish the format changing

deercoder/exp-code,DeercoderPractice/exp-code,deercoder/exp-code,DeercoderPractice/exp-code,deercoder/exp-code,DeercoderPractice/exp-code,DeercoderPractice/exp-code,deercoder/exp-code,DeercoderPractice/exp-code,deercoder/exp-code,deercoder/exp-code,DeercoderPractice/exp-code