今天是第五十二天，依舊是動態規劃專題

300.最長遞增子序列 

 class Solution {
    public int lengthOfLIS(int[] nums) {
        int[] dp = new int[nums.length];
        Arrays.fill(dp, 1);
        for (int i = 0; i < dp.length; i++) {
            for (int j = 0; j < i; j++) {
                if (nums[i] > nums[j]) {
                    dp[i] 
 
= Math.max(dp[i], dp[j] + 1);
                }
            }
        }
        int res = 0;
        for (int i = 0; i < dp.length; i++) {
            res = Math.max(res, dp[i]);
        }
        return res;
    
    }
}

子序列的入門題

674. 最長連續遞增序列 

class Solution {
    public int findLengthOfLCIS(int
 
[] nums) {
        int n = nums.length;
        int[] dp = new int[n];
        for (int i = 0; i < n; i++) {
            dp[i] = 1;
        }
        int res = 1;
        for (int i = 0; i < n - 1; i++) {
            if (nums[i + 1] > nums[i]) {
                dp[i + 1] = dp[i] + 1;
            }
            res 
 
= res > dp[i + 1] ? res : dp[i + 1];
        }
        return res;
    }
}

非常的模版

718. 最長重複子陣列 

class Solution {
    public int findLength(int[] nums1, int[] nums2) {
        int result = 0;
        int n = nums1.length;
        int m = nums2.length;
        int[][] dp = new int[n + 1][m + 1];
        
        for (int i = 1; i < n + 1; i++) {
            for (int j = 1; j < m + 1; j++) {
                if (nums1[i - 1] == nums2[j - 1]) {
                    dp[i][j] = dp[i - 1][j - 1] + 1;
                    result = Math.max(result, dp[i][j]);
                }
            }
        }
        
        return result;
    }
}

沒太懂這個二維陣列dp，明天再看看

子序列問題有點難