and assuming the two variables have been properly initialized, which of the following is/are valid expressions or

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1 Instructions: Submit your answers to these questions to the Curator as OQ04 by the posted due date and time. No late submissions will be accepted. For questions 1 through 3, assume the type definition: struct _PersonData { int Age; int Height; int Weight; ; typedef struct _PersonData PersonData; 1. Which of the following are valid for creating and initializing a PersonData variable? 1) PersonData Fred; Fred.Age = 25; Fred.Height = 73; Fred.Weight = 110; 2) PersonData Fred = {25, 73, 110; 3) PersonData Fred; PersonData.Age = 25; PersonData.Height = 73; PersonData.Weight = 110; 2. Given the variable declarations: PersonData Jim, Fred; and assuming the two variables have been properly initialized, which of the following are valid expressions or statements involving PersonData variables? 1) Jim = Fred; 2) Jim == Fred 3) printf("%d %d %d", Fred); 3. Given the variable declarations: PersonData Jim, Fred; and assuming the two variables have been properly initialized, which of the following is/are valid expressions or statements involving PersonData variables? 1) Jim.Age++; 2) Fred[2] = 4; 3) Fred.Age >= Jim.Age 1

2 For questions 4 through 7, consider the following declarations (which are all valid C code): #define MaxEmployees 1000 struct _Personnel { char* Name; int IDNum; double HourlyPayRate; ; typedef struct _Personnel Personnell; Personnel Emp5 = { "Joe Bob Hokie", , 19.87, Emp7 = { "Haskell Hoo IV", , 9.32 ; Personnel Staff[MaxEmployees]; Assume that the array Staff[] has been initialized so that all fields of all the array elements have logically correct values. 4. Which of the following C statements could be used to print the name field of the variable Emp5? 1) printf("%s\n", Emp5.Name); 2) printf("%s\n", Emp5->Name); 3) printf("%s\n", Name); 5. Which of the following C expressions could be used to compare the variables Emp5 and Emp7? 1) Emp5 == Emp7 2) Emp7 = Emp7 3) Emp5 <= Emp7 4) All of the above 6. The statement: printf("%s\n", Staff[17].Name); 1) prints the name of the employee with ID number 17 2) prints the name of the employee whose Personnel record is stored in Staff[] at index 17 3) is syntactically illegal since you can't print a struct variable with printf() 4) None of these 7. The statement: Staff[17] = Emp5; 1) copies the contents of the Personnel record at index 17 into the variable Emp5 2) copies the contents of the variable Emp5 into the Personnel record at index 17 3) swaps the contents of the variable Emp5 and the Personnel record at index 17 4) is syntactically illegal 5) None of these 2

3 For questions 8 and 9, consider the declarations and function: struct _Bar { int Foo[5]; int Size; ; typedef struct _Bar Bar; Bar x = {{2, 5, 9, 11, 17, 5, These are legal initializations. y = {{0, 3, 6, 3; Bar AddBar(const Bar* A, const Bar* B) { Bar NewBar; if (A->Size <= B->Size) NewBar.Size = A->Size; else NewBar.Size = B->Size; for (int Idx = 0; Idx < NewBar.Size; Idx++) NewBar.Foo[Idx] = A->Foo[Idx] + B->Foo[Idx]; return NewBar; Suppose the following statement is executed: Bar z = AddBar(x, y); 8. The value of z.foo[2] would be: 1) 0 2) 2 3) 3 4) 5 5) 6 6) 9 7) 11 8) 15 9) None of these 9. The value of z.size would be: 1) 0 2) 1 3) 2 Suppose the following statement is executed: 4) 3 5) 4 6) 5 Bar* pb = &x; 7) Which of the following C statements would print the Size field of the variable x? 1) printf("%d\n", pb->size); 2) printf("%d\n", (*pb).size); 3) printf("%d\n", pb.size); 3

4 11. Which of the following C statements would print the Foo field of the variable X? 1) printf("%d %d %d %d %d\n", pb->foo); 2) printf("%d %d %d %d %d\n", (*pb).foo); 3) for (int i = 0; i < pb->size; i++) printf("%5d", pb->foo[i]); For questions 12 through 20, assume the type definition: struct _Trip { char* Origin; char* Destination; uint32_t Miles; uint32_t Minutes; ; typedef struct _Trip Trip; For questions 12 and 13, consider the following incomplete function definition: Resets the Time field of a Trip variable, if the given parameter is nonnegative. void settime( T, int Minutes) { Line 1 if (Minutes >= 0) { = Minutes; Line How should the blank in Line 1 be filled? 1) const Trip* 2) Trip* const 3) Trip* 4) Any of these will do equally well 5) 1 or 2 only 6) 1 or 3 only 13. How should the blank in Line 2 be filled? 1) T.Minutes 2) Trip.Minutes 3) T->Minutes 4) Any of these will do 5) 1 or 2 only 6) 1 or 3 only 4

5 For questions 14 through 16, consider the following incomplete function definition: If the destination of Leg1 is the same as the origin of Leg2, set Merged to represent a trip from the origin of Leg1 to the destination of Leg2, with the correct total mileage and time. Pre: Leg1 and Leg2 point to properly-initialized Trip objects Merged points to an uninitialized Trip object Post: *Leg1 and *Leg2 are unchanged *Merged is changed as described above Return true if the merge succeeds and false otherwise. bool mergetrips( Leg1, Leg2, Merged) { if ( ) { strcpy(merged->origin, Leg1->Origin); strcpy(merged->destination, Leg2->Destination); Merged->Miles = Leg1->Miles + Leg2->Miles; Merged->Minutes = Leg1->Minutes + Leg2->Minutes; return true; return false; When you answer the following questions, pay careful attention to the parts of the implementation of the function that are shown above. 14. What is the best way to fill the first blank in the formal parameter list? 1) Trip* 2) Trip* const 3) const Trip* 4) const Trip* const 5) Any of these will do 6) 1 or 2 only 8) 2 or 4 only 9) 3 or 4 only 10) None of these 15. What is the best way to fill the third blank in the formal parameter list? 1) Trip* 2) Trip* const 3) const Trip* 4) const Trip* const 5) Any of these will do 6) 1 or 2 only 8) 2 or 4 only 9) 3 or 4 only 10) None of these 16. What is the best way to fill the blank in the if-condition? 1) strcmp(leg1->origin, Leg->Destination) 2) strcmp(leg1->destination, Leg2->Origin) 3) strcmp(leg1->origin, Leg2->Destination) == 0 4) strcmp(leg1->destination, Leg2->Origin) == 0 5) strcmp(leg1->origin, Leg2->Destination)!= 0 6) strcmp(leg1->destination, Leg2->Origin)!= 0 7) 1 and 5 only 8) 2 and 6 only 9) None of these 5

6 For question 17, consider the following incomplete function definition: Pre: *porigin and *pdestination are zero-terminated C strings tlist[0:ntrips-1] are properly initialized Trip objects Return the index of the first Trip object in the array that matches the given origin and destination; UINT32_MAX if no match is found. uint32_t findtrip(const char* const porigin, const char* const pdestination, const Trip* const tlist, uint32_t ntrips) { if ( porigin == NULL pdestination == NULL tlist == NULL ) uint32_t idx; for (idx = 0; idx < ntrips; idx++) { if ( strcmp(porigin, ) == 0 && Line 1 strcmp(pdestination, ) == 0 ) 2 return idx; 17. What is the best way to fill the blank in Line 1? 1) tlist[idx].destination 2) tlist[idx].origin 3) tlist[idx]->destination 4) tlist[idx]->origin 5) All of them are equally good 7) 2 and 4 only For question 18, consider the following incomplete function definition, slightly changed from the previous question, but with the same precondition and return comments: uint32_t findtrip(const char* const porigin, const char* const pdestination, const Trip* const tlist, uint32_t ntrips) { if ( porigin == NULL pdestination == NULL tlist == NULL ) uint32_t idx; Trip* currtrip = &tlist[0]; for (idx = 0; idx < ntrips; idx++) { if ( strcmp(porigin, ) == 0 && Line 1 strcmp(pdestination, ) == 0 ) 2 return idx; currtrip++; 6

7 18. What is the best way to fill the blank in Line 2? 1) (*currtrip).destination 2) (*currtrip).origin 3) currtrip->destination 4) currtrip->origin 5) All of them are equally good 7) 2 and 4 only For questions 19 and 20, consider the following incomplete function definition: Pre: *ptrip is a properly initialized Trip object Post: The Origin and Destination fields of *ptrip have been swapped; no other changes have been made to *ptrip void reversetrip(trip* const ptrip) { if ( ptrip == NULL ) return; swap the Origin and Destination fields 19. The parameter ptrip is passed as "char* const". What is the effect of that? 1) The function can change where ptrip points. 2) The function can change the contents of the Trip object that ptrip points to. 3) The function cannot change where ptrip points. 4) The function cannot change the contents of the Trip object that ptrip points to. 6) 1 and 4 only 8) 2 and 4 only 9) None of these 20. Which of the following code fragments could be used to correctly complete the implementation of the function? 1) strcpy(ptrip->origin, ptrip->destination); strcpy(ptrip->destination, ptrip->origin); 2) char* tmp; strcpy(tmp, ptrip->destination); strcpy(ptrip->destination, ptrip->origin); strcpy(ptrip->origin, ptrip->destination); free(tmp); 3) char* tmp = malloc( strlen(ptrip->destination) + 1 ); strcpy(tmp, ptrip->destination); strcpy(ptrip->destination, ptrip->origin); strcpy(ptrip->origin, ptrip->destination); free(tmp); 5) All of these 6) 1and 2 only 7) 1 and 3 only 8) 2 and 4 only 9) 3 and 4 only 10) None of these 4) char* tmp = ptrip->origin; ptrip->origin = ptrip->destination; ptrip->destination = tmp; 7