/**
* Method 1: Delete the input element x
* and meanwhile keep the length of array after deleted n
* @param a the array
* @param n the length of array after deleted.
* @param x the element that need to be deleted.
*/
static void delete(int[] a, int n, int x) {
// preconditions: [0] <= ... <= a[n-1], and n <= a.length;
// postconditions: a[0] <= ... <= a[n-2], and x is deleted;
int i = 0; // find the first index i for which a[i] > x:
while (i < n && a[i] <= x) {
++i;
}
// shift {a[i],...,a[n-1]} into {a[i-1],...,a[n-2]}:
if (i < n - 1) {
System.arraycopy(a, i, a, i - 1, n - i);
}
a[n - 1] = 0;
}
/**
* Gets the number of nodes in the specified list;
* Fox example, if list is {33,55,77,99}, the size(list) will be return 4;
*
* @param list
* @return
*/
static int size(Node list) {
int size = 0;
while (list != null) {
++ size;
list = list.next;
}
return size;
}
/**
* Gets the sum of nodes in the specified list;
* Fox example, if list is {33,55,77,99}, the size(list) will be return 254;
* @param list
* @return
*/
static int sum(Node list){
int sum = 0;
while(list != null){
sum += list.data;
list = list.next;
}
return sum;
}
/**
// precondition: the specified list has at least two nodes;
// postcondition: the last node in the list has been deleted;
For example, if list is {22, 44, 66, 88}, then removeLast(list)will change it to {22, 44,66}.
* @param list
*/
void removeLast(Node list){
if(list == null || list.next == null)
{
//throw new IllegalStatException();
}
//{33,55,77,99}
while(list.next.next != null) {
list = list.next;
}
list.next = null;
}
/**
*
* @param list
* @return
*/
static Node copy(Node list)
{
if(list == null)
{
return null;
}
Node clone = new Node(list.data);
for (Node p = list, q = clone; p != null; p = p.next, q = q.next)
{
q.next = p.next;
}
return clone;
}
/**
* Get a new list that contains copies of the p-q nodes of the specified list,
* starting with node number p(starting with 0).
* For example, if listis {22, 33, 44, 55, 66, 77, 88, 99}, then sublist(list, 2, 7)will
* return the new list {44, 55, 66, 77, 88}. Note that the two lists must be completely independent of each other.
* Changing one list should have no effect upon the other.
* @param list
* @param m
* @param n
* @return
*/
Node sublist(Node list, int m, int n) {
if (m < 0 || n < m) {
throw new IllegalArgumentException();
} else if (n == m) {
return null;
}
//55,22,11,33
for (int i = 0; i < m; i++) {
list = list.next;
}
Node clone = new Node(list.data);
Node p = list, q = clone;
for (int i = m + 1; i < n; i++) {
if (p.next == null) {
throw new IllegalArgumentException();
}
q.next = new Node(p.next.data);
p = p.next;
q = q.next;
}
return clone;
}