Interview

Answers for questions faced during interview

QUESTION #1:

Write a Java method that takes an array of "sets" of String objects, and determines whether all sets in the array are equivalent.

Each "set" in the input array is represented as an array of String objects, in no particular order, and possibly containing duplicates. Nevertheless, when determining whether two of these "sets" are equivalent, you should disregard order and duplicates. For example, the sets represented by these arrays are all equivalent:

{"a", "b"} {"b", "a"} {"a", "b", "a"}

The signature for your method should be:

public static boolean allStringSetsIdentical(String[ ][ ] sets)

Examples of the method in operation:

allStringSetsIdentical(new String[][] {{"a","b"},{"b","b","a"},{"b","a"}}) returns true

allStringSetsIdentical(new String[][] {{"a","b"},{"a"},{"b"}}) returns false

QUESTION #2:

// // The following Java code is responsible for creating an HTML "SELECT" // list of U.S. states, allowing a user to specify his or her state. This might // be used, for instance, on a credit card transaction screen. // // Please rewrite this code to be "better". Submit your replacement code, and // please also submit a few brief comments explaining why you think your code // is better than the sample. // // (For brevity, this sample works for only 5 states. The real version would // need to work for all 50 states. But it is fine if your rewrite shows only // the 5 states here.) //

public class StateUtils {

// // Generates an HTML select list that can be used to select a specific // U.S. state. // public static String createStateSelectList() { return "<select name="state">\n" + "<option value="Alabama">Alabama\n" + "<option value="Alaska">Alaska\n" + "<option value="Arizona">Arizona\n" + "<option value="Arkansas">Arkansas\n" + "<option value="California">California\n" // more states here + "\n" ; }

// // Parses the state from an HTML form submission, converting it to // the two-letter abbreviation. // public static String parseSelectedState(String s) { if (s.equals("Alabama")) { return "AL"; } if (s.equals("Alaska")) { return "AK"; } if (s.equals("Arizona")) { return "AZ"; } if (s.equals("Arkansas")) { return "AR"; } if (s.equals("California")) { return "CA"; } // more states here }

// // Displays the full name of the state specified by the two-letter code. // public static String displayStateFullName(String abbr) { { if (abbr.equals("AL")) { return "Alabama"; } if (abbr.equals("AK")) { return "Alaska"; } if (abbr.equals("AZ")) { return "Arizona"; } if (abbr.equals("AR")) { return "Arkansas"; } if (abbr.equals("CA")) { return "California"; } // more states here }

}

QUESTION #3:

Write a Java method with the following method signature that takes a String and returns a String formatted so that it satisfies the requirements below. It may need to insert newlines and/or delete spaces.

Method Signature: public static String wrapText(String text, int maxCharsPerLine)

Definitions and Assumptions: A word is a nonempty sequence of characters that contains no spaces and no newlines. Lines in the return String are separated by the newline character, '\n'. Words on each line are separated by spaces. Assume that the String argument does not contain any whitespace characters other than spaces and newlines.

Requirements:

1. Newlines in the String argument are preserved.
2. Words in the return String are separated by either a single space or by one or more newlines.
3. Lines in the return String do not start or end with any spaces.
4. When constructing the return String from the String argument, each word in the String argument with at most maxCharsPerLine characters should not be broken up. Each word in the String argument with more than maxCharsPerLine characters should be broken up so that all of the other requirements are satisfied.
5. The String argument may contain lines longer than maxCharsPerLine. Newlines should be added so that each line in the return String has at most maxCharsPerLine characters. To determine where newlines should be added, try to fit as many words as possible on a line (while keeping line length at most maxCharsPerLine and satisfying the other requirements) before starting a new line.

Question #4

Return the first repeated Name

Question #5 Pacal's Triangle - optimal space complexity

Question #6 A small frog wants to get to the other side of a river. The frog is currently located at position 0, and wants to get to position X. Leaves fall from a tree onto the surface of the river. You are given a non-empty zero-indexed array A consisting of N integers representing the falling leaves. A[K] represents the position where one leaf falls at time K, measured in minutes. The goal is to find the earliest time when the frog can jump to the other side of the river. The frog can cross only when leaves appear at every position across the river from 1 to X.