Add TT6.java

Miscellaneous/TT6.java

@@ -0,0 +1,72 @@
+import java.util.*;
+
+public class TT6 {
+
+    public static List<int[]> compress(int[] a) {
+        List<int[]> result = new ArrayList<>();
+        int count = 1;
+
+        for (int i = 1; i < a.length; i++) {
+            while (i < a.length && a[i] == a[i - 1]) {
+                ++count;
+                ++i;
+            }
+
+            result.add(new int[] { a[i - 1], count });
+            count = 1;
+        }
+
+        return result;
+    }
+
+    public static int dotProduct(List<int[]> v1, List<int[]> v2) {
+        int result = 0;
+
+        int i = 0, j = 0;
+
+        while (i < v1.size() && j < v2.size()) {
+            int[] a = v1.get(i), b = v2.get(j);
+
+            int counter = Math.min(a[1], b[1]);
+
+            a[1] -= counter;
+            b[1] -= counter;
+
+            result += a[0] * b[0] * counter;
+
+            if (a[1] == 0) {
+                ++i;
+            }
+
+            if (b[1] == 0) {
+                ++j;
+            }
+        }
+
+        return result;
+    }
+
+    public static void main(String[] args) {
+        int[] a = new int[] { 1, 1, 4, 4, 4, 4, 7, 7, 7, 7, 7, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 };
+        int[] b = new int[] { 2, 2, 5, 5, 5, 5, 5, 5, 5, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 };
+
+        List<int[]> result1 = compress(a);
+        List<int[]> result2 = compress(b);
+
+        for (int[] pair : result1) {
+            System.out.println(pair[0] + ", " + pair[1]);
+        }
+
+        System.out.println("\n---\n");
+
+        for (int[] pair : result2) {
+            System.out.println(pair[0] + ", " + pair[1]);
+        }
+
+        System.out.println("\n---\n");
+
+        System.out.println(dotProduct(result1, result2) == 291);
+
+        return;
+    }
+}