// CSE340 Spring 2018 HOMEWORK 4 (code part). // DUE DATE: Saturday Match 17 by 11:59 pm. // This code contains a number of questions. // You should answer the questions and provide justification for your answers. // All questions assume that the code is compiled according to ANSI C99 // standard. To compile it according to C99 standard execute the // following from the command prompt (not visual studio!) // // gcc -std=gnu99 CSE340S18_HW4.c // #include  #include  struct T { int a; int *b; struct T *next; } ; struct T p0; struct T *p1; struct T **p2; int *p; int *q; int main() { int i; struct T* cursor; p1 = (struct T *) malloc(sizeof(struct T)); p2 = (struct T **) malloc(sizeof(struct T *)); p = (int *) malloc(sizeof(int)); q = (int *) malloc(sizeof(int)); *p = *q; p0.next = p1; (*p1).a = *p; (*p1).next = &p0; *p2 = (*p1).next; //------------------------------------------------------------------ // Question1. Draw a box-circle diagram for p,q, p0, p1, p2 and the // memory allocated above at this point //------------------------------------------------------------------ { struct T *a[5]; struct T **b[5]; int i,j; a[0] = (struct T*) malloc(sizeof(struct T)); p2 = &(a[0]); (*a[0]).next = p1; //----------------------------------------------------------- // Question 2. Draw a box-circle diagram for p1, p2, a[] // and the memory allocated above at this point //------------------------------------------------------------ for (i = 1; i < 4; i++) { a[i] = (struct T*) malloc(sizeof(struct T)); (*a[i]).next = a[i-1]; (*a[i]).a = i; b[i] = &a[i]; (**b[i]).next = *b[i]; } (*p1).next = a[2]; //------------------------------------------------------------------ // Question 3. Explain the output produced by the // following loop //------------------------------------------------------------------ cursor = a[0]; for (j = 0; j < 5; j++) { printf("%d ",(*cursor).a); cursor = (*cursor).next; } printf(" "); //------------------------------------------------------------------ // Question 4. Draw a box-circle diagram of ALL the variables // and the memory allocated up to this point? // what locations are garbage at this point? //------------------------------------------------------------------ //------------------------------------------------------------------ // Question 5. Give an alias for a[2] at this point. // This alias should not include the names "a" !! // This might be tricky and you might want to skip // it and do other parts first. //------------------------------------------------------------------ { struct T *b[6]; int j; for (i = 1; i < 6; i++) { b[i] = (struct T*) malloc(sizeof(struct T)); (*b[i]).next = a[i%4]; (*b[i]).b = &i; } //------------------------------------------------------------------ // Question 6. Explain the output produced by the // following loop //------------------------------------------------------------------ for (j = 1; j < 6; j++) { printf("%d ",(*(*b[j]).next).a); } printf(" "); } //------------------------------------------------------------------ // Question 7. What are the dangling references at // this point? //------------------------------------------------------------------ //------------------------------------------------------------------ // Question 8. What locations are garbage at this point? //------------------------------------------------------------------ } //------------------------------------------------------------------ // Question 9. What are the dangling references at this point. //------------------------------------------------------------------ }