Add LongestCommonSubsequence

Author: jcazevedo

src/main/java/com/packt/datastructuresandalg/lesson4/lcs/LongestCommonSubsequence.java

@@ -0,0 +1,25 @@
+package com.packt.datastructuresandalg.lesson4.lcs;
+
+public class LongestCommonSubsequence {
+    public int length(String x, String y) {
+        int m = x.length();
+        int n = y.length();
+        int[][] c = new int[m + 1][n + 1];
+        for (int i = 1; i <= m; i++) {
+            for (int j = 1; j <= n; j++) {
+                if (x.charAt(i - 1) == y.charAt(j - 1))
+                    c[i][j] = c[i - 1][j - 1] + 1;
+                else
+                    c[i][j] = Math.max(c[i - 1][j], c[i][j - 1]);
+            }
+        }
+        return c[m][n];
+    }
+
+    public static void main(String[] args) {
+        String s1 = "ACCGGTCGAGTGCGCGGAAGCCGGCCGAA";
+        String s2 = "GTCGTTCGGAATGCCGTTGCTCTGTAAA";
+        LongestCommonSubsequence lcs = new LongestCommonSubsequence();
+        System.out.println("Length of longest common subsequence = " + lcs.length(s1, s2));
+    }
+}