TT6.java

importjava.util.*;

publicclassTT6 {

publicstaticList<int[]> compress(int[] a) {
List<int[]> result = newArrayList<>();
intcount = 1;

for (inti = 1; i < a.length; i++) {
while (i < a.length && a[i] == a[i - 1]) {
 ++count;
 ++i;
 }

result.add(newint[] { a[i - 1], count });
count = 1;
 }

returnresult;
 }

publicstaticintdotProduct(List<int[]> v1, List<int[]> v2) {
intresult = 0;

inti = 0, j = 0;

while (i < v1.size() && j < v2.size()) {
int[] a = v1.get(i), b = v2.get(j);

intcounter = 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;
 }
 }

returnresult;
 }

publicstaticvoidmain(String[] args) {
int[] a = newint[] { 1, 1, 4, 4, 4, 4, 7, 7, 7, 7, 7, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2 };
int[] b = newint[] { 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;
 }
}