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How many pointers are required to reverse a link list?
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Answer / prits
Using 3 pointers:
curr, next, result pointers, curr points to current node,
next obviously points to the next node, result points to
the new reversed linked list
void reverse_single_linked_list(struct node** headRef)
{
struct node* result = NULL;
struct node* current = *headRef;
struct node* next;
while (current != NULL)
{
next = current->next; // tricky: note the next node
current->next = result; // move the node onto the result
result = current;
current = next;
}
*headRef = result;
}
| Is This Answer Correct ? | 14 Yes | 1 No |
Answer / patrick
You cannot must have a pointer to a pointer if you want to
modify the pointer.
void reverse(node** head)
{
node* cur = *head;
*head = null;
while (cur)
{
node* next = cur->next;
cur->next = *head;
*head = cur;
cur = next;
}
}
Besides the head pointer, you will need two local pointers.
| Is This Answer Correct ? | 4 Yes | 1 No |
Answer / vivek
using 2 pointer:
void reverse(node* head_in_out)
{
if(head_in_out)
{
node* aCurr = head_in_out;
node* aNext = NULL;
while (aCurr)
{
head_in_out = aCurr->next;
aCurr->next = aNext;
aNext = aCurr;
aCurr = head_in_out;
}
}
}
| Is This Answer Correct ? | 1 Yes | 2 No |
Answer / vivek
# 3 using 2 pointer:
void reverse(node* head_in_out)
{
if(head_in_out)
{
node* aCurr = head_in_out;
node* aNext = NULL;
while (aCurr)
{
head_in_out = aCurr->next;
aCurr->next = aNext;
aNext = aCurr;
aCurr = head_in_out;
}
head_in_out = aNext; // Bug in above 3rd answer.
}
}
| Is This Answer Correct ? | 1 Yes | 2 No |
If P is the population on the first day of the year, B is the birth rate, and D is the death rate, the estimated population at the end of the year is given by the formula: The population growth rate is given by the formula: B – D Write a program that prompts the user to enter the starting population, birth and death rates, and n, the number of years. The program should then calculate and print the estimated population after n years. Your program must have at least the following functions: 1. growthRate: This function takes its parameters the birth and death rates, and it returns the population growth rate. 2. estimatedPopulation: This function takes its parameters the current population, population growth rate, and n, the number of years. It returns the estimated population after n years Your program should not accept a negative birth rate, negative death rate, or a population less than 2.
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