# REVERSE-A-LINKED-LIST hackerrank Solution - Correct, Optimal and Working

``````/*
*  Author: Arpit Bhayani
*  https://arpitbhayani.me
*/
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <climits>
#include <deque>
#include <iostream>
#include <list>
#include <limits>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>

#define ll long long

#define MIN(a, b) a < b ? a : b
#define MAX(a, b) a > b ? a : b

using namespace std;

int readline(char *str) {
int i = 0;
char ch;
while((ch = getchar()) != '\n') {
str[i++] = ch;
}
str[i] = '\0';
return i;
}

struct Node {
int data;
struct Node *next;
};

void Print(struct Node *head) {
struct Node *p = head;
while(p) {
printf("%d\n", p->data);
p = p->next;
}
}

struct Node * new_node(int v) {
struct Node * p = (struct Node *) calloc(1, sizeof(struct Node));
p->data = v;
return p;
}

struct Node * Reverse(struct Node * head) {

if(head == NULL) {
}

struct Node * p = NULL;
struct Node * q = head;
struct Node * r = q->next;

while(q) {
r = q->next;
q->next = p;
p = q;
q = r;
}

return p;
}

int main(int argc, char *argv[]) {
struct Node * head = new_node(1);