longest common subsequency problem , hactobefest2022

Longest common subsequence.cpp

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+#include <bits/stdc++.h>
+using namespace std;
+
+
+int LCS(string str1, string str2)
+{
+  int length1 = str1.size();
+  int lenght2 = str2.size();
+
+  int dp[length1 + 1][lenght2 + 1];	// Declared the DP 2-D matrix ;
+  for (int i = 0; i <= length1; i++)
+    {
+    for (int j = 0; j <= lenght2; j++)
+	{
+	    if (i == 0 || j == 0)
+	         {
+	              dp[i][j] = 0;	//If one of the string length becomes 0 LCS will be 0 ;
+		 }
+	     else if (str1[length1 - i] == str2[lenght2 - j])
+	           {
+	                dp[i][j] = 1 + dp[i - 1][j - 1];	// when the first Character Matches 
+	               }
+	      else
+		 {
+	      int a = dp[i - 1][j];	// when first Character of first string is
+		                        //considered in the Longest Common Sequency solution .
+          int b = dp[i][j - 1];	// when first Character of second string is
+			                    //considered in the Longest Common Sequency solution .*/
+          int c = dp[i - 1][j - 1]; 	// when none of the first character is considered in the solution .
+          dp[i][j] = max(a, max(b, c));
+			}
+		}
+	}
+   return dp[length1][lenght2];
+}
+
+
+int main()    
+{
+	string str1, str2;
+	cin >> str1;
+	cin >> str2;
+	cout << "LCS of " << str1 << " and " << str2 << " is " << LCS(str1, str2) << endl;
+	return 0;
+}