Complete the body of this function. Use a queue of characters to store the input line as it is being read. size_t counter( )

// Precondition: There is a line of input waiting to be read from cin.
// Postcondition: A line of input has been read from cin, up to but not
// including the newline character. The return value of the function
// is the number of times that the LAST character of the line appeared
// somewhere in this line.
// EXAMPLE Input: ABBXDXXZX
// The value returned by counter would be 4 for this input since there
// are 4 X's in the input line.
{
size_t answer = 0;
queue q;