CS 434 Exam 3: Problem Solutions and Additional Questions, Exams of Computer Science

Download CS 434 Exam 3: Problem Solutions and Additional Questions and more Exams Computer Science in PDF only on Docsity! CS 434 Exam 3 Name ________________________ Spring 2004 This exam has 7 problems, and each problem is worth at least 15 points, so there is some built-in extra credit. 1. Convert this Triangle program to an equivalent TAM program. let var a:Integer; var b:Integer; var c:Integer in begin getint(var a); getint(var b); c:=(a+7)*(b-6); putint(c*c) end } 4. Consider again the C++ program from problem 3. For each of the nine classes, draw the class object (method table). 5. Consider the C++ declaration below. Assume a byte-addressable machine such that each double uses 8 bytes, each int uses 4 bytes, each char uses 1 byte, and each float uses 4 bytes. Also assume that s[0][0].d[0] is at location 0, and two-dimensional arrays are stored in row-major order. struct {double d[3]; int i; char c[8]; float f;} s[100][10]; a. Determine the total size in bytes for variable s. b. Determine the location of s[10][0].c[4] c. Determine the location of s[50][5].d[1] 6. Consider the C++ program below. void f(int*& a, int*& b) { if (*a > *b) a=b; else { delete b; b=a; } } void main( ) { int *p, *q, *r; p=q=new int; r=new int; cin >> *q; cin >> *r; if (*r > 0) f(q, r); else f(r, q); cout << *p << endl; cout << *q << endl; cout << *r << endl; } a. Can any sequence of input values cause a memory leak (garbage)? If so, specify such input values, and draw a picture that clearly represents the situation in the heap just before the program ends. b. Can any sequence of input values cause a dangling pointer? If so, specify such input values, and draw a picture that clearly represents the situation in the heap just before the program ends. c. Very briefly state how some programming languages (not C++) prevent both memory leaks and dangling pointers.