题目1： 1143. 最长公共子序列

代码：

class Solution {
public:
    int longestCommonSubsequence(string text1, string text2) {
        int m = text1.length();
        int n = text2.length();
        vector<vector<int>> dp(m + 1, vector<int>(n + 1, 0));

        int maxLen = 0;
        for(int i = 1; i <= m; i++) {
            for(int j = 1; j <=n; j++) {
                if(text1[i - 1] == text2[j - 1]) dp[i][j] = dp[i - 1][j - 1] + 1;
                else dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
                maxLen = max(maxLen, dp[i][j]);
            }
        }
        return maxLen;
    }
};

题目2: 1035. 不相交的线
代码：

class Solution {
public:
    int maxUncrossedLines(vector<int>& nums1, vector<int>& nums2) {
        int m = nums1.size();
        int n = nums2.size();
        vector<vector<int>> dp(m + 1, vector<int>(n + 1, 0));

        int maxLen = 0;
        for(int i = 1; i <= m; i++) {
            for(int j = 1; j <= n; j++) {
                if(nums1[i - 1] == nums2[j - 1]) dp[i][j] = dp[i - 1][j - 1] + 1;
                else dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
                maxLen = max(maxLen, dp[i][j]);
            }
        }
        return maxLen;
    }
};

题目3: 53. 最大子数组和
代码：

class Solution {
public:
    int maxSubArray(vector<int>& nums) {
        int n = nums.size();
        if(n == 0) return 0;
        vector<int> dp(n);
        int maxSum = dp[0] = nums[0];
        for(int i = 1; i < n; i++) {
            dp[i] = max(dp[i - 1] + nums[i], nums[i]);
            maxSum = max(maxSum, dp[i]);
        }
        return maxSum;
    }
};

题目4: 392. 判断子序列

代码：

class Solution {
public:
    bool isSubsequence(string s, string t) {
        int m = s.length();
        int n = t.length();
        vector<vector<int>> dp(m + 1, vector<int>(n + 1, 0));

        for(int i = 1; i <= m; i++) {
            for(int j = 1; j <= n; j++) {
                if(s[i - 1] == t[j - 1]) dp[i][j] = dp[i - 1][j - 1] + 1;
                else dp[i][j] = dp[i][j - 1];
            }
        }
        return dp[m][n] == m;
    }
};