LCS

BasePractice · Dec 13, 2024 · 6fd133e · 6fd133e
1 parent 56e04ad
commit 6fd133e
Show file tree

Hide file tree

Showing 4 changed files with 48 additions and 10 deletions.
diff --git a/vol6/src/main/java/ru/mifi/practice/vol6/tree/search/Main.java b/vol6/src/main/java/ru/mifi/practice/vol6/tree/search/Main.java
@@ -7,11 +7,11 @@
 public abstract class Main {
     public static void main(String[] args) {
         Consumer<BinaryTree<Integer>> generator = tree -> tree.add(8).add(3).add(6).add(1).add(4).add(7).add(10).add(14).add(13);
-//        test("Binary", new BinarySearchTree<>(), generator);
-//        test("AVL", new AVL<>(), generator);
-//        System.out.println("Вырожденное дерево");
+        test("Binary", new BinarySearchTree<>(), generator);
+        test("AVL", new AVL<>(), generator);
+        System.out.println("Вырожденное дерево");
         generator = tree -> tree.add(1).add(2).add(3).add(4).add(5).add(6).add(7).add(8).add(9);
-//        test("Binary", new BinarySearchTree<>(), generator);
+        test("Binary", new BinarySearchTree<>(), generator);
         test("AVL", new AVL<>(), generator);
     }
 

diff --git a/vol7/src/main/java/ru/mifi/practice/vol7/Main.java b/vol7/src/main/java/ru/mifi/practice/vol7/Main.java
@@ -7,6 +7,7 @@
 import ru.mifi.practice.vol7.fibonacci.FibonacciDynamicus;
 import ru.mifi.practice.vol7.fibonacci.FibonacciMemorized;
 import ru.mifi.practice.vol7.fibonacci.FibonacciRecursion;
+import ru.mifi.practice.vol7.subsequence.LongestCommonSubsequence;
 
 import java.util.List;
 
@@ -27,7 +28,8 @@ public static void main(String[] args) {
         List<Backpack.Item> putting = backpack.putting(items);
         System.out.println("         Backpack : " + putting);
         distance("Lev.Recur", new Levenshtein.LevenshteinRecursion(), "boobs", "bomb");
-        distance("Lev.Dynam", new Levenshtein.LevenshteinDynamicus(), "boobs", "bomb");
+        distance("Lev.Dynam", new Levenshtein.VagnerFisherDynamicus(), "boobs", "bomb");
+        lcs("Sub.Commo", new LongestCommonSubsequence.Default(), "mouse", "house");
     }
 
     private static void fibonacci(String name, Fibonacci fibonacci) {
@@ -47,4 +49,12 @@ private static void distance(String name, Distance distance, String word1, Strin
         System.out.println(prefix + "Val : " + d);
         System.out.println(prefix + "Cnt : " + counter);
     }
+
+    private static void lcs(String name, LongestCommonSubsequence subsequence, String word1, String word2) {
+        Counter counter = new Counter.Default();
+        String prefix = String.format("LCS.%s.", name);
+        int d = subsequence.longestCommonSubsequence(word1, word2, counter);
+        System.out.println(prefix + "Val : " + d);
+        System.out.println(prefix + "Cnt : " + counter);
+    }
 }
diff --git a/vol7/src/main/java/ru/mifi/practice/vol7/distance/Levenshtein.java b/vol7/src/main/java/ru/mifi/practice/vol7/distance/Levenshtein.java
@@ -7,7 +7,7 @@
 public interface Levenshtein extends Distance {
 
     abstract class AbstractLevenshtein implements Levenshtein {
-        protected static int costOfSubstitution(char a, char b) {
+        protected static int cost(char a, char b) {
             return a == b ? 0 : 1;
         }
 
@@ -29,15 +29,15 @@ public int distance(String s1, String s2, Counter counter) {
             }
             counter.increment();
             int substitution = distance(s1.substring(1), s2.substring(1), counter)
-                + costOfSubstitution(s1.charAt(0), s2.charAt(0));
+                + cost(s1.charAt(0), s2.charAt(0));
             int insertion = distance(s1, s2.substring(1), counter) + 1;
             int deletion = distance(s1.substring(1), s2, counter) + 1;
 
             return min(substitution, insertion, deletion);
         }
     }
 
-    final class LevenshteinDynamicus extends AbstractLevenshtein {
+    final class VagnerFisherDynamicus extends AbstractLevenshtein {
         @Override
         public int distance(String s1, String s2, Counter counter) {
             int[][] table = new int[s1.length() + 1][s2.length() + 1];
@@ -51,8 +51,7 @@ public int distance(String s1, String s2, Counter counter) {
                     } else if (j == 0) {
                         table[i][j] = i;
                     } else {
-                        table[i][j] = min(table[i - 1][j - 1]
-                                + costOfSubstitution(s1.charAt(i - 1), s2.charAt(j - 1)),
+                        table[i][j] = min(table[i - 1][j - 1] + cost(s1.charAt(i - 1), s2.charAt(j - 1)),
                             table[i - 1][j] + 1,
                             table[i][j - 1] + 1);
                     }

diff --git a/vol7/src/main/java/ru/mifi/practice/vol7/subsequence/LongestCommonSubsequence.java b/vol7/src/main/java/ru/mifi/practice/vol7/subsequence/LongestCommonSubsequence.java
@@ -0,0 +1,29 @@
+package ru.mifi.practice.vol7.subsequence;
+
+import ru.mifi.practice.vol7.Counter;
+
+public interface LongestCommonSubsequence {
+    int longestCommonSubsequence(String text1, String text2, Counter counter);
+
+    final class Default implements LongestCommonSubsequence {
+
+        @Override
+        public int longestCommonSubsequence(String text1, String text2, Counter counter) {
+            int n = text1.length();
+            int m = text2.length();
+            int[][] table = new int[n + 1][m + 1];
+            for (int i = 1; i <= n; i++) {
+                counter.increment();
+                for (int j = 1; j <= m; j++) {
+                    counter.increment();
+                    if (text1.charAt(i - 1) == text2.charAt(j - 1)) {
+                        table[i][j] = table[i - 1][j - 1] + 1;
+                    } else {
+                        table[i][j] = Math.max(table[i][j - 1], table[i - 1][j]);
+                    }
+                }
+            }
+            return table[n][m];
+        }
+    }
+}