sopherwang

/* Copyright 2013 Google Inc.
   Licensed under Apache 2.0: http://www.apache.org/licenses/LICENSE-2.0.html */

package com.example.latlnginterpolation;

import android.animation.ObjectAnimator;
import android.animation.TypeEvaluator;
import android.animation.ValueAnimator;
import android.annotation.TargetApi;
import android.os.Build;

sopherwang

    public List<Interval> insert(List<Interval> intervals, Interval newInterval)
    {
        if (intervals == null || newInterval == null)
        {
            return intervals;
        }
        if (intervals.size() == 0)
        {
            intervals.add(newInterval);
            return intervals;

sopherwang

    public ArrayList<Interval> merge(ArrayList<Interval> intervals)
    {
        ArrayList<Interval> result = new ArrayList<Interval>();

        if ((intervals == null) || (intervals.size() == 0))
            return result;

        Comparator<Interval> comparator = new Comparator<Interval>()
        {
            @Override

sopherwang

    public int[] twoSum(int[] numbers, int target)
    {
        HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
        for (int i = 0; i < numbers.length; i++)
        {
            if (map.get(target - numbers[i]) != null)
            {
                if (map.get(target - numbers[i]) <= i)
                {
                    return new int[] { map.get(target - numbers[i]) + 1, i + 1 };

sopherwang

    public int atoi(String str) {
        //1. space
        //2. +/-
        //3. invalid character
        //4. null
        //5. MAX_INT and MIN_INT
        
        if (str == null || str.length() == 0)
            return 0;

sopherwang

    public int climbStairsDP(int n)
    {
        //dp
        //dp[i]: how many ways to reach i.(i < n)
        if (n <= 1)
        {
            return n;
        }
        int[] dp = new int[n + 1];
        dp[0] = 1;

sopherwang

public boolean isValidBST(TreeNode root)
    {
        return isValidate(root, Integer.MIN_VALUE, Integer.MAX_VALUE);
    }

    private boolean isValidate(TreeNode root, int min, int max)
    {
        if (root == null)
        {
            return true;

sopherwang

public double pow(double x, int n)
    {
        if (n == 0)
        {
            return 1;
        }
        if (n < 0)
        {
            return 1.0 / power(x, -n);
        }

sopherwang

    public int ladderLength(String start, String end, Set<String> dict)
    {
        if (start.length() != end.length())
        {
            return 0;
        }
        if (dict == null || dict.size() == 0)
        {
            return 0;
        }