Iterator

gistfile1.txt

import java.util.Iterator;
import java.util.NoSuchElementException;

public class Converter {

    Iterator<Integer> convert(Iterator<Iterator<Integer>> it) {
        return new Iterator<Integer>() {

            /**
             * Current step of iterator
             */
            Iterator<Integer> current = it.next();

            /**
             * Check next step of iterator
             * @return true or false
             */
            @Override
            public boolean hasNext() {
                boolean hasNext = false;
                if (current.hasNext()) {
                    hasNext = true;
                } else {
                    while (it.hasNext()) {
                        this.current = it.next();
                        if (current.hasNext()) {
                            hasNext = true;
                            break;
                        }
                    }
                }
                return hasNext;
            }

            /**
             * Check next int in iterator and return it, else go to next iterator and return int of it
             * @return next value of iterator
             */
            @Override
            public Integer next() {
                if (!this.hasNext()) {
                    throw new NoSuchElementException();
                }
                return current.next();
            }
        };
    }
}