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// java java/ch-2.java
import java.util.List;
import java.util.stream.IntStream;
import java.util.stream.Collectors;
public class ch_2 {
static int task2 ( Integer k, List<Integer> ns ) {
Integer[] ints = ns.toArray(new Integer[0]);
return IntStream.range(0, ints.length)
.filter(i -> Integer.bitCount(i) == k)
.mapToObj(i -> ints[i])
.collect(Collectors.summingInt(Integer::intValue));
}
// Test harness
static int test_number = 1;
static void plan ( Integer count ) { System.out.printf("1..%d\n", count); }
static boolean is ( Integer got, Integer expected, String desc ) {
boolean ret = got == expected;
System.out.printf("%s %d - %s\n", (ret ? "ok" : "not ok"), test_number++, desc);
return ret;
}
public static void main(String[] args) {
record Testcase ( Integer expected, Integer in_k, List<Integer> in_nums ) {}
List<Testcase> tst = List.of(
new Testcase( 17, 1, List.of(2, 5, 9, 11, 3) ),
new Testcase( 11, 2, List.of(2, 5, 9, 11, 3) ),
new Testcase( 2, 0, List.of(2, 5, 9, 11, 3) )
);
plan(tst.size());
for (Testcase t : tst) {
is( task2(t.in_k, t.in_nums), t.expected, "k=" + t.in_k);
}
}
}
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