Review questions on structs
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1. TopHalf

function C = topHalf(A)
% Refer to Lecture 21.
% Suppose A is a length-50 structure array with two fields
% Assume A(k).name is a string that names a state and A(k).pop
% is an integer whose value is the states population.
% Assume that the states are ordered alphabetically.
% C is a length-25 cell array of strings that names all the
% states whose populations are above the median state population.
% The states should be ordered alphabetically in C.




2. BigTriplets
function N = BigTriplets(A)
% Refer to the Lectures 20 and 21.
% Suppose A is a length-50 structure array with two fields.
% Assume A(k).name is a string that names a state and A(k).pop
% is an integer whose value is the states population.
% We say that three different states form a "big triplet" if
% the sum of their populations is greater than 15 million.
% N is the number of big triplets.




3.  Point struct

% Given a structure array Pts where each structure has two fields, x and y,
% sort Pts so that the structures are in the order of 
% increasing distance from (0,0)