car renting example, Java

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//'main' method must be in a class 'Rextester'.
//Compiler version 1.8.0_111

import java.util.Arrays;
import java.util.Comparator;
import java.util.HashSet;

class Rextester {
  public static void main(String[] args) {
    int n = 101;
    CarRentingTuple[] tuples = new CarRentingTuple[n];
    for (int i = 0; i < n; ++i) {
      tuples[i] = new CarRentingTuple(i, i+4);
    }
    solve(tuples);
  }
  
    public static void solve(CarRentingTuple[] tuples){

Arrays.sort(tuples, Comparator.comparingInt(o -> o.start));

// Figure out which tuples have colliding priorities
        for(int i = 0; i < tuples.length; i++) {
            for(int j = i + 1; j < tuples.length && tuples[j].start <= tuples[i].end; j++) {
                tuples[i].set.add(tuples[j]);
                tuples[j].set.add(tuples[i]);
            }
        }

// Keep removing tuple with most colliding priorities until there are no more colliding priorities
        int removed = 0;
        while(hasCollision(tuples)) {
            CarRentingTuple worst = tuples[0];
            for(CarRentingTuple t : tuples)
                if(t.set.size() > worst.set.size())
                    worst = t;

for(CarRentingTuple t : worst.set)
                t.set.remove(worst);
            worst.set.clear();
            worst.start = -1;
            removed++;
        }

// Construct new array without removed tuples
        CarRentingTuple[] result = new CarRentingTuple[tuples.length - removed];
        for(int i = 0, j = 0; j < tuples.length; j++)
            if(tuples[j].start != -1)
                result[i++] = tuples[j];

for (CarRentingTuple t : result) {
          System.out.print( t.toString() );
        }
        System.out.println();
        System.out.println( "result.length: " + result.length );
        // Note.writenl(result);
    }

private static boolean hasCollision(CarRentingTuple[] tuple){
        for(CarRentingTuple t : tuple)
            if(t.set.size() > 0)
                return true;
        return false;
    }

}

class CarRentingTuple {
    HashSet<CarRentingTuple> set = new HashSet<>();
    int start, end;
    CarRentingTuple(int a, int b) {
        start = Math.min(a, b);
        end = Math.max(a, b);
    }
    public String toString(){
        return "(" + start + ", " + end + ")";
    }
}

[ + ] Show input
Compilation time: 1.03 sec, absolute running time: 0.23 sec, cpu time: 0.27 sec, memory peak: 25 Mb, absolute service time: 1,27 sec