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hackerrank triplets
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;
public class Solution {
// Complete the countTriplets function below.
static long countTriplets(List<Long> arr, long r) {
long total = 0;
Map<Long, Long> count = new HashMap<>(); // count of ints
Map<Long, Long> tuplets = new HashMap<>(); // map 2nd -> count of links
for (int i = 0; i < arr.size(); ++i) {
//System.out.printf("i=%d\n", i);
long val = arr.get(i);
// inc total
if (val % r == 0 && tuplets.containsKey(val / r)) {
total += tuplets.get(val / r);
//System.out.printf("%dx %d -> %d -> %d\n", t.count, t.first, val / r, val);
}
// create links/tuplets
if (tuplets.containsKey(val)) {
tuplets.put(val, tuplets.get(val) + count.get(val/r));
//System.out.printf("%dx %d -> %d\n", tuplets.get(val).count, tuplets.get(val).first, val);
} else if (val % r == 0 && count.containsKey(val / r)) {
//System.out.printf("%dx %d -> %d\n", count.get(val/r), val/r, val);
tuplets.put(val, count.get(val / r));
}
// inc count
if (count.containsKey(val))
count.put(val, count.get(val)+1);
else
count.put(val, 1L);
}
return total;
}
public static void main(String[] args) throws IOException {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
String[] nr = bufferedReader.readLine().replaceAll("\\s+$", "").split(" ");
//int n = Integer.parseInt(nr[0]);
long r = Long.parseLong(nr[1]);
List<Long> arr = Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
.map(Long::parseLong)
.collect(toList());
long ans = countTriplets(arr, r);
bufferedWriter.write(String.valueOf(ans));
bufferedWriter.newLine();
bufferedReader.close();
bufferedWriter.close();
}
}
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