最长公共子序列最长公共子串

Posted 2020-11-13 ymjyqsx

最长公共子序列：

class Solution {
public:
    int findLength(vector<int>& A, vector<int>& B) {
        int len1 = A.size();
        int len2 = B.size();
        if(len1 == 0 || len2 == 0)
            return 0;
        
        vector<vector<int>> result(len1+1,vector<int>(len2+1));
        for(int i = 0;i <= len1;i++){
            result[i][0] = 0;
        }
        for(int i = 0;i <= len2;i++){
            result[0][i] = 0;
        }
        for(int i = 1;i <= len1;i++){
            for(int j = 1;j <= len2;j++){
                if(A[i-1] == B[j-1])
                    result[i][j] = result[i-1][j-1] + 1;
                else
                    result[i][j] = max(result[i-1][j],result[i][j-1]);
            }
        }
        return result[len1][len2];
    }
};

最长公共子串

class Solution {
public:
    int findLength(vector<int>& A, vector<int>& B) {
        int len1 = A.size();
        int len2 = B.size();
        if(len1 == 0 || len2 == 0)
            return 0;
        
        vector<vector<int>> result(len1+1,vector<int>(len2+1));
        for(int i = 0;i <= len1;i++){
            result[i][0] = 0;
        }
        for(int i = 0;i <= len2;i++){
            result[0][i] = 0;
        }
        for(int i = 1;i <= len1;i++){
            for(int j = 1;j <= len2;j++){
                if(A[i-1] == B[j-1])
                    result[i][j] = result[i-1][j-1] + 1;
                else
                    result[i][j] = 0;
            }
        }
        int maxnum = 0x80000000;
        for(int i = 1;i <= len1;i++){
            for(int j = 1;j <= len2;j++){
                if(result[i][j] > maxnum)
                    maxnum = result[i][j];
            }
        }
        return maxnum;
    }
};