62 lines
1.6 KiB
Java
62 lines
1.6 KiB
Java
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import java.util.Scanner;
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/**
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*
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* @author Afrizal Fikri (https://github.com/icalF)
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*
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*/
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public class LongestIncreasingSubsequence {
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public static void main(String[] args) throws Exception {
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Scanner sc = new Scanner(System.in);
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int n = sc.nextInt();
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int ar[] = new int[n];
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for (int i = 0; i < n; i++) {
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ar[i] = sc.nextInt();
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}
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System.out.println(LIS(ar));
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}
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private static int upperBound(int[] ar, int l, int r, int key) {
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while (l < r-1) {
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int m = (l + r) / 2;
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if (ar[m] >= key)
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r = m;
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else
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l = m;
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}
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return r;
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}
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public static int LIS(int[] array) {
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int N = array.length;
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if (N == 0)
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return 0;
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int[] tail = new int[N];
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int length = 1; // always points empty slot in tail
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tail[0] = array[0];
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for (int i = 1; i < N; i++) {
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// new smallest value
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if (array[i] < tail[0])
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tail[0] = array[i];
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// array[i] extends largest subsequence
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else if (array[i] > tail[length-1])
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tail[length++] = array[i];
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// array[i] will become end candidate of an existing subsequence or
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// Throw away larger elements in all LIS, to make room for upcoming grater elements than array[i]
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// (and also, array[i] would have already appeared in one of LIS, identify the location and replace it)
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else
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tail[upperBound(tail, -1, length-1, array[i])] = array[i];
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}
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return length;
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}
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}
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