FunctionalTwo.java

/**
 * 
 */
package coding.bat.solutions;

import java.util.List;

/**
 * @author Aman Shekhar
 *
 */
public class FunctionalTwo {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub

	}

	// --------------------------------------------------------------------------------------------

	// Given a list of integers, return a list of the integers, omitting any that
	// are less than 0.
	//
	//
	// noNeg([1, -2]) → [1]
	// noNeg([-3, -3, 3, 3]) → [3, 3]
	// noNeg([-1, -1, -1]) → []

	public List<Integer> noNeg(List<Integer> nums) {
		nums.removeIf(n -> (n < 0));
		return nums;
	}

	// --------------------------------------------------------------------------------------------

	// Given a list of non-negative integers, return a list of those numbers except
	// omitting any that end with 9. (Note: % by 10)
	//
	//
	// no9([1, 2, 19]) → [1, 2]
	// no9([9, 19, 29, 3]) → [3]
	// no9([1, 2, 3]) → [1, 2, 3]

	public List<Integer> no9(List<Integer> nums) {
		nums.removeIf(n -> ((n % 10) == 9));
		return nums;
	}

	// --------------------------------------------------------------------------------------------

	// Given a list of integers, return a list of those numbers, omitting any that
	// are between 13 and 19 inclusive.
	//
	//
	// noTeen([12, 13, 19, 20]) → [12, 20]
	// noTeen([1, 14, 1]) → [1, 1]
	// noTeen([15]) → []

	public List<Integer> noTeen(List<Integer> nums) {
		nums.removeIf(n -> ((n >= 13) && (n <= 19)));
		return nums;
	}

	// --------------------------------------------------------------------------------------------

	// Given a list of strings, return a list of the strings, omitting any string
	// that contains a "z". (Note: the str.contains(x) method returns a boolean)
	//
	//
	// noZ(["aaa", "bbb", "aza"]) → ["aaa", "bbb"]
	// noZ(["hziz", "hzello", "hi"]) → ["hi"]
	// noZ(["hello", "howz", "are", "youz"]) → ["hello", "are"]

	public List<String> noZ(List<String> strings) {
		strings.removeIf(n -> (n.contains("z")));
		return strings;
	}

	// --------------------------------------------------------------------------------------------

	// Given a list of strings, return a list of the strings, omitting any string
	// length 4 or more.
	//
	//
	// noLong(["this", "not", "too", "long"]) → ["not", "too"]
	// noLong(["a", "bbb", "cccc"]) → ["a", "bbb"]
	// noLong(["cccc", "cccc", "cccc"]) → []

	public List<String> noLong(List<String> strings) {
		strings.removeIf(n -> (n.length() >= 4));
		return strings;
	}

	// --------------------------------------------------------------------------------------------

	// Given a list of strings, return a list of the strings, omitting any string
	// length 3 or 4.
	//
	//
	// no34(["a", "bb", "ccc"]) → ["a", "bb"]
	// no34(["a", "bb", "ccc", "dddd"]) → ["a", "bb"]
	// no34(["ccc", "dddd", "apple"]) → ["apple"]

	public List<String> no34(List<String> strings) {
		strings.removeIf(n -> (n.length() == 3) || (n.length() == 4));
		return strings;
	}

	// --------------------------------------------------------------------------------------------

	// Given a list of strings, return a list where each string has "y" added at its
	// end, omitting any resulting strings that contain "yy" as a substring
	// anywhere.
	//
	//
	// noYY(["a", "b", "c"]) → ["ay", "by", "cy"]
	// noYY(["a", "b", "cy"]) → ["ay", "by"]
	// noYY(["xx", "ya", "zz"]) → ["xxy", "yay", "zzy"]
	public List<String> noYY(List<String> strings) {
		strings.replaceAll(n -> n + "y");
		strings.removeIf(n -> n.contains("yy"));
		return strings;
	}

	// --------------------------------------------------------------------------------------------

	// Given a list of non-negative integers, return a list of those numbers
	// multiplied by 2, omitting any of the resulting numbers that end in 2.
	//
	//
	// two2([1, 2, 3]) → [4, 6]
	// two2([2, 6, 11]) → [4]
	// two2([0]) → [0]

	public List<Integer> two2(List<Integer> nums) {
		nums.replaceAll(n -> n * 2);
		nums.removeIf(n -> (n % 10 == 2));
		return nums;
	}

	// --------------------------------------------------------------------------------------------

	// Given a list of integers, return a list of those numbers squared and the
	// product added to 10, omitting any of the resulting numbers that end in 5 or
	// 6.
	//
	//
	// square56([3, 1, 4]) → [19, 11]
	// square56([1]) → [11]
	// square56([2]) → [14]

	public List<Integer> square56(List<Integer> nums) {
		nums.replaceAll(n -> (n * n) + 10);
		nums.removeIf(n -> ((n % 10 == 5) || (n % 10 == 6)));
		return nums;
	}

}