Midterm 2 from Winter 2007 had the following two problems about arrays. The rest of the
midterm was about material we have not gotten to yet. Remember that your midterm will also
cover functions, and chapter 10 of the book.

Problem 1 (15 pts):
Will the following program compile? If so, will it work correctly, i.e. do what the comment says it will do? If not, what errors can occur?  If incorrect, how
can the program be fixed?

/* This program reads in a  list of 10 integers, and then asks the user to select which element in the list
to print, and then prints that element */

#include<stdio.h>
main()
{
int a[10], i, col;

printf("Input a list of ten integers\n");
for (i = 0; i < 10; i++) scanf("%d", &a[i]);

printf ("Specify from 1 to 10 which element in the list you want to print out\n");
scanf("%d", &col);
printf ("%d", a[col]);
}


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Problem 2: (25 points)
Suppose A is a two-dimensional integer array with n rows and n columns (the same number of
rows as columns); suppose A already has
values in all cells. Write the part of a program that adds together all the values in A along the
main diagonal of A, i.e. along the diagonal from the top left to the bottom right. Use the integer
variable sum to hold the result.