39 lines
800 B
Java
39 lines
800 B
Java
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import java.util.*;
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// https://en.wikipedia.org/wiki/Longest_increasing_subsequence
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public class Lis {
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public static int[] getLis(int[] x) {
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int n = x.length;
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int[] len = new int[n];
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Arrays.fill(len, 1);
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int[] pred = new int[n];
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Arrays.fill(pred, -1);
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int bi = 0;
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for (int i = 1; i < n; i++) {
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for (int j = 0; j < i; j++) {
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if (x[j] < x[i] && len[i] < len[j] + 1) {
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len[i] = len[j] + 1;
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pred[i] = j;
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}
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}
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if (len[bi] < len[i]) {
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bi = i;
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}
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}
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int cnt = len[bi];
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int[] res = new int[cnt];
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for (int i = bi; i != -1; i = pred[i]) {
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res[--cnt] = x[i];
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}
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return res;
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}
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// Usage example
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public static void main(String[] args) {
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int[] a = { 1, 5, 4, 2, 3, 7, 6 };
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int[] lis = getLis(a);
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System.out.println(Arrays.toString(lis));
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}
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}
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