consider our implementation of the stack adt using the python listand suppose we had used the front of the list as the top of the stack and the end of the list as the base what impactif anywould this have on the run time of the various stack operations show that all of the stack adt operations have constant time in the worst case when implemented as linked list would it buy us anything to use tail reference with the linked list structure used to implement the stack adtexplain your answer evaluate the run time of the isvalidsource(function where is the number of characters in the +source file programming projects write and test program that extracts postfix expressions from the userevaluates the expressionand prints the results you may require that the user enter numeric values along with the operators and that each component of the expression be separated with white space the isvalidsource(function can be used to evaluate +source filebut it is incomplete brackets encountered inside comments and literal strings would not be paired with those found elsewhere in the program (ac+comments can be specified using //which starts comment that runs to the end of the current lineand the token pair /*/which encloses comment that can span multiple lines extend the function to skip over brackets found inside +comments (bc+literal strings are denoted by enclosing characters within double quotes ("string"and literal characters are denoted by enclosing character within single quotes (' 'extend the function to skip over brackets found inside +literal strings and characters design and implement function that evaluates prefix expression stored as text string implement the findpath()reset()and draw(methods for the maze class implement complete maze solving application using the components introduced earlier in the modify the solve(method to return vector containing tuples representing the path through the maze we can design and build postfix calculator that can be used to perform simple arithmetic operations the calculator consists of single storage component that consists of an operand stack the operations performed by the stack always use the top two values of the stack and store the result back on the