代码随想录算法训练营20期|第五十六天|动态规划part14|● 1143.最长公共子序列 ● 1035.不相交的线 ● 53. 最大子序和 动态规划

•  1143.最长公共子序列 

class Solution {
    public int longestCommonSubsequence(String text1, String text2) {
        int[][] dp = new int[text1.length() + 1][text2.length() + 1];

        for (int i = 1; i <= text1.length(); i++) {
            char c1 = text1.charAt(i - 1);
            for(int j = 1; j <= text2.length(); j++) {
                char c2 = text2.charAt(j - 1);
                if (c1 == c2) {
                    dp[i][j] = dp[i - 1][j - 1] + 1;
                } else {
                    dp[i][j] = Math.max(dp[i - 1][j], dp[i][j - 1]);
                }
            }
        }
        return dp[text1.length()][text2.length()];
    }
}

•  1035.不相交的线   

class Solution {
    public int maxUncrossedLines(int[] nums1, int[] nums2) {
        int n1 = nums1.length;
        int n2 = nums2.length;
        int[][] dp = new int[n1 + 1][n2 + 1];

        for (int i = 1; i <= n1; i++) {
            for (int j = 1; j <= n2; j++) {
                if (nums1[i - 1] == nums2[j - 1]) {
                    dp[i][j] = dp[i - 1][j - 1] + 1;
                } else {
                    dp[i][j] = Math.max(dp[i-1][j], dp[i][j - 1]);
                }
            }
        }
        return dp[n1][n2];
    }
}

•  53. 最大子序和  动态规划 

class Solution {
    public int maxSubArray(int[] nums) {
        int maxToCur = nums[0];
        int sum = nums[0];

        for (int i = 1; i < nums.length; i++) {
            maxToCur = Math.max(maxToCur + nums[i], nums[i]);
            sum = Math.max(maxToCur, sum);
        }
        return sum;
    }
}