UncleGarden

/**
 * 1.1 Implement an algorithm to determine if a string has all unique
 * characters. What if you cannot use additional data structures?
 *
 * @author Jiateng
 */
public class CC1_1 {

    /**
     * sort the characters in the string, then compare from the begin to the end

UncleGarden

/**
 * 1.2 Implement a function void reverse(char* str) in C or C++ which reverses a
 * null-terminated string.
 *
 * @author Jiateng
 */
public class CC1_2 {

    //Time O(n), Space O(n)
    public static String reverse1(String target) {

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/**
 * 1.3 Given two strings, write a method to decide if one is a permutation of
 * the other.
 *
 * @author Jiateng
 */
public class CC1_3 {
 
    //Time O(n), Space O(1)
    public static boolean permutation(String s1, String s2) {

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/**
 * 1.4 Write a method to replace all spaces in a string with'%20'. You may
 * assume that the string has sufficient space at the end of the string to hold
 * the additional characters, and that you are given the "true" length of the
 * string. (Note: if implementing in Java, please use a character array so that
 * you can perform this operation in place.) EXAMPLE
 *
 * Input: "Mr John Smith "
 *
 * Output: "Mr%20Dohn%20Smith"

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/**
 * 1.5 Implement a method to perform basic string compression using the counts
 * of repeated characters. For example, the string aabcccccaaa would become
 * a2blc5a3. If the "compressed" string would not become smaller than the
 * original string, your method should return the original string.
 *
 * @author Jiateng
 */
public class CC1_5 {

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/**
 *
 * 1.6 Given an image represented by an NxN matrix, where each pixel in the
 * image is 4 bytes, write a method to rotate the image by 90 degrees. Can you
 * do this in place?
 *
 * @author Jiateng
 */
public class CC1_6 {

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/**
 * 1.7 Write an algorithm such that if an element in an MxN matrix is 0, its
 * entire row and column are set to 0.
 *
 * @author Jiateng
 */
public class CC1_7 {

    public static void setZeroes(int[][] matrix) {
        boolean firstrow = false;

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/**
 * 2.1 Write code to remove duplicates from an unsorted linked list. FOLLOW UP
 * How would you solve this problem if a temporary buffer is not allowed?
 *
 * public class ListNode { int val; ListNode next; }
 *
 * @author Jiateng
 */
public class CC2_1 {

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/**
 * 2.2 Implement an algorithm to find the kth to last element of a singly linked
 * list.
 *
 * @author Jiateng
 */
public class CC2_2 {

    //Time O(n), Space O(1)
    public static<Item> Item find(LinkedList<Item> list, int k) {

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/**
 * Implement an algorithm to delete a node in the middle of a singly linked
 * list, given only access to that node. EXAMPLE Input: the node c from the
 * linked list a->b->c->d->e Result: nothing isreturned, but the new linked list
 * looks like a- >b- >d->e
 *
 * @author Jiateng
 */
public class CC2_3 {