Level 1 programming task write the function getpop(char mycode[3]), which takes in a two-digit string representing the state or territory code and returns the associated state or territory population. the function should open and scan the file uspops. txt for the input two-digit code, mycode. if mycode is not found in the file, the function should return -1. make sure to close the file once the file reading is complete. level 2 programming task write the function getrank(int mypop), which takes in an integer representing a state or territory population and returns its rank. the function should open the file uspops. txt and compare mypop to the populations for all states and territories. example: california is the most populous state with 39536653 people, so when getrank(39536653) is called, the function should return 1 (because there are 0 states with a greater population than 39536653). make sure to close the file once the file reading is complete. level 3 programming task write the function state_totalpop(state* headstate), which takes in a pointer to the head element of a linked list and returns the total population sum for all elements in the list.