The janitor left the classrooms inapple-pie orderevery night.The underlined words mean -

Be in apple-pie order (idiom): 
English Meaning - To be perfectly arranged and tidy. 
Bangle Meaning - যেখানে যা থাকা উচিত সেখানে তা-ই আছে; নিখুঁত শৃঙ্খলাপূর্ণ।

Example Sentence - Their house is always in apple-pie order.

Source: Cambridge Dictionary.