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61 lines
1.2 KiB
61 lines
1.2 KiB
package class09;
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import java.util.Arrays;
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import java.util.Comparator;
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// 本题测试链接 : https://leetcode.com/problems/russian-doll-envelopes/
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public class Code04_EnvelopesProblem {
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public static int maxEnvelopes(int[][] matrix) {
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Envelope[] arr = sort(matrix);
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int[] ends = new int[matrix.length];
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ends[0] = arr[0].h;
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int right = 0;
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int l = 0;
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int r = 0;
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int m = 0;
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for (int i = 1; i < arr.length; i++) {
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l = 0;
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r = right;
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while (l <= r) {
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m = (l + r) / 2;
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if (arr[i].h > ends[m]) {
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l = m + 1;
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} else {
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r = m - 1;
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}
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}
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right = Math.max(right, l);
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ends[l] = arr[i].h;
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}
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return right + 1;
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}
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public static class Envelope {
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public int l;
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public int h;
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public Envelope(int weight, int hight) {
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l = weight;
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h = hight;
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}
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}
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public static class EnvelopeComparator implements Comparator<Envelope> {
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@Override
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public int compare(Envelope o1, Envelope o2) {
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return o1.l != o2.l ? o1.l - o2.l : o2.h - o1.h;
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}
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}
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public static Envelope[] sort(int[][] matrix) {
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Envelope[] res = new Envelope[matrix.length];
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for (int i = 0; i < matrix.length; i++) {
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res[i] = new Envelope(matrix[i][0], matrix[i][1]);
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}
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Arrays.sort(res, new EnvelopeComparator());
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return res;
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}
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}
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