Russian Doll Envelopes

 1 public class Solution {
 2     public int maxEnvelopes(int[][] envelopes) {
 3         if (envelopes.length < 2) {
 4             return envelopes.length;
 5         }
 6         
 7         Arrays.sort(envelopes, new Comparator<int[]>() {
 8             @Override
 9             public int compare(int[] a, int b[]) {
10                 return Integer.compare(a[1], b[1]);
11             }
12         });
13         
14         int[] dp = new int[envelopes.length];
15         int result = 1;
16         for (int i = 0; i < envelopes.length; i++) {
17             dp[i] = 1;
18             for (int j = 0; j < i; j++) {
19                 if (envelopes[i][0] > envelopes[j][0] &&
20                     envelopes[i][1] > envelopes[j][1]) {
21                         dp[i] = Math.max(dp[i], dp[j] + 1);
22                     }
23             }
24             result = Math.max(dp[i], result);
25         }
26         return result;
27     }
28 }

Last DP element MAY NOT be the answer since the max number can happened between.

posted on 2016-06-29 15:10 keepshuatishuati 阅读(155) 评论(0) 编辑收藏举报