Create longestCommonSubsequence.cpp

Author: SteffiKeranJ

Dynamic-Programming/longestCommonSubsequence.cpp

@@ -0,0 +1,48 @@
+/**
+Given two strings text1 and text2, return the length of their longest common subsequence. If there is no common subsequence, return 0.
+
+A subsequence of a string is a new string generated from the original string with some characters (can be none) deleted without changing the relative order of the remaining characters.
+
+For example, "ace" is a subsequence of "abcde".
+A common subsequence of two strings is a subsequence that is common to both strings.
+
+ 
+
+Example 1:
+
+Input: text1 = "abcde", text2 = "ace" 
+Output: 3  
+Explanation: The longest common subsequence is "ace" and its length is 3.
+Example 2:
+
+Input: text1 = "abc", text2 = "abc"
+Output: 3
+Explanation: The longest common subsequence is "abc" and its length is 3.
+Example 3:
+
+Input: text1 = "abc", text2 = "def"
+Output: 0
+Explanation: There is no such common subsequence, so the result is 0.
+
+**/
+
+
+class Solution {
+public:
+    int longestCommonSubsequence(string text1, string text2) {
+        int m = text1.size();
+        int n = text2.size();
+        // vector<vector<int>> dp(1001, vector<int>(1001));
+        int dp[1001][1001] = {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] = 1 + dp[i-1][j-1];
+                else
+                    dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
+            }
+        }
+        return dp[m][n];
+    }
+};