fix: handle constant inputs in `LongestIncreasingSubsequence::findLISLen' (#5160)

fix: handle constant inputs in `LongestIncreasingSubsequence::findLISLen`
This commit is contained in:
Piotr Idzik
2024-05-17 11:54:22 +02:00
committed by GitHub
parent 0f42e995a4
commit bf9d0ed66a
2 changed files with 56 additions and 20 deletions

View File

@ -1,7 +1,5 @@
package com.thealgorithms.dynamicprogramming;
import java.util.Scanner;
/**
* @author Afrizal Fikri (https://github.com/icalF)
*/
@ -9,20 +7,6 @@ public final class LongestIncreasingSubsequence {
private LongestIncreasingSubsequence() {
}
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int[] arr = new int[n];
for (int i = 0; i < n; i++) {
arr[i] = sc.nextInt();
}
System.out.println(LIS(arr));
System.out.println(findLISLen(arr));
sc.close();
}
private static int upperBound(int[] ar, int l, int r, int key) {
while (l < r - 1) {
int m = (l + r) >>> 1;
@ -36,7 +20,7 @@ public final class LongestIncreasingSubsequence {
return r;
}
private static int LIS(int[] array) {
public static int LIS(int[] array) {
int N = array.length;
if (N == 0) {
return 0;
@ -73,14 +57,17 @@ public final class LongestIncreasingSubsequence {
*/
// A function for finding the length of the LIS algorithm in O(nlogn) complexity.
public static int findLISLen(int[] a) {
int size = a.length;
final int size = a.length;
if (size == 0) {
return 0;
}
int[] arr = new int[size];
arr[0] = a[0];
int lis = 1;
for (int i = 1; i < size; i++) {
int index = binarySearchBetween(arr, lis, a[i]);
int index = binarySearchBetween(arr, lis - 1, a[i]);
arr[index] = a[i];
if (index > lis) {
if (index == lis) {
lis++;
}
}