एक अनुकूलित (optimized) विधि का उपयोग करके n नोड्स वाले बाइनरी ट्री का व्यास (diameter) ज्ञात करने की समय जटिलता (time complexity) क्या है?

What is the worst-case time complexity of inserting 'n' elements into an initially empty linked list such that the linked list remains sorted?

What are the contents of an initially empty stack (from bottom to top) after performing the following operations? PUSH(A); PUSH(B); PUSH(C); POP; PUSH(D); POP; POP; PUSH(E); PUSH(F); POP;