Sep 23, 2014 · Sep 23, 2014 · Sep 25, 2014 · Sep 25, 2014 · Sep 25, 2014 · Sep 26, 2014
diff --git a/facebook/SortWeight.java b/facebook/SortWeight.java
 package Algorithms.facebook;

 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedList;

 public class SortWeight {
    public static void main(String[] args) {
        String input1 = "crab hotdog 9.0 chicken 9.2 pig 9.2";
        String input2 = "pizza 1 hotdog 2.0";
        String input3 = "pizza 500 hotdog 2.0";
        String input4 = "pizza 500 2.0";

        LinkedList<String> list1 = sortWeight(input1);
        LinkedList<String> list2 = sortWeight(input2);
        LinkedList<String> list3 = sortWeight(input3);
        LinkedList<String> list4 = sortWeight(input4);

        System.out.println(list1.toString());
        System.out.println(list2.toString());
        System.out.println(list3.toString());
        System.out.println(list4.toString());
    }

    public static LinkedList<String> sortWeight(String input) {
        LinkedList<String> ret = new LinkedList<String>();
        if (input == null) {
            return ret;
        }

        String[] strs = input.split(" ");

        float defautWeight = 5;

        // 当weight = -1，表示这一组食物-重量链还未完成
        String food = null;
        float weight = 0;

        // 记录某重量下所有的食物
        HashMap<Float, ArrayList<String>> map = new HashMap<Float, ArrayList<String>>();

        // Go through the string.
        for (String s: strs) {
            // 上一次的food-weight对已经结束
            if (weight != -1) {
                food = s;
                weight = -1;
            } else {
                float tmp = stringToNumber(s);
                // This is a float, so just add a food to the list.
                if (tmp != -1) {
                    weight = tmp;
                    addFoodToMap(map, food, weight);
                } else {
                    // This is not a float, means that there should be
                    // a new food.
                    addFoodToMap(map, food, defautWeight);

                    // 开始新一轮的食物-重量链
                    food = s;
                    weight = -1;
                }
            }
        }

        //System.out.println(map.toString());

        if (weight == -1) {
            addFoodToMap(map, food, defautWeight);
        }

        ArrayList<Float> array = new ArrayList<Float>(map.keySet());
        Collections.sort(array);

        for (Float w: array) {
            ArrayList<String> foods = map.get(w);
            for (String element: foods) {
                ret.addFirst(element);
            }
        }

        return ret;
    }

    public static void addFoodToMap(HashMap<Float, ArrayList<String>> map, String food,
             float weight) {
        // 把上一次的食物-重量终结
        ArrayList<String> list = map.get(weight);
        if (list != null) {
            // 在相应的重量下添加食物
            list.add(food);
        } else {
            // 新建一个重量链
            ArrayList<String> listNew = new ArrayList<String>();
            listNew.add(food);
            map.put(weight, listNew);
        }
    }

    // when it is not a float, return -1;
    public static float stringToNumber(String cur) {
        float result = -1;

        try {
            result = Float.parseFloat(cur);
        } catch (NumberFormatException e) {
            result = -1;
        }

        return result;
    }
 }
diff --git a/tree/MinDepth.java b/tree/MinDepth.java
        把 null 设置为返回一个最大值，这样的话，如果出现空子树，它不会影响最小值。但是如果左
        右均为空，则应返回1（即是仅仅为根节点）

        而且这种做法更加合理。 因为如果是空树，应该是无法到达才是。这时就应该将值设置为最大。
        而且这种做法更加合理。 因为如果是空树，应该是无法到达才是。这时就应该将值设置为最大。
     * */
 publicintminDepthHelp(TreeNoderoot) {
 if (root ==null) {
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,115 @@
		package Algorithms.facebook;

		import java.util.ArrayList;
		import java.util.Collections;
		import java.util.HashMap;
		import java.util.HashSet;
		import java.util.Iterator;
		import java.util.LinkedList;

		public class SortWeight {
		public static void main(String[] args) {
		String input1 = "crab hotdog 9.0 chicken 9.2 pig 9.2";
		String input2 = "pizza 1 hotdog 2.0";
		String input3 = "pizza 500 hotdog 2.0";
		String input4 = "pizza 500 2.0";

		LinkedList<String> list1 = sortWeight(input1);
		LinkedList<String> list2 = sortWeight(input2);
		LinkedList<String> list3 = sortWeight(input3);
		LinkedList<String> list4 = sortWeight(input4);

		System.out.println(list1.toString());
		System.out.println(list2.toString());
		System.out.println(list3.toString());
		System.out.println(list4.toString());
		}

		public static LinkedList<String> sortWeight(String input) {
		LinkedList<String> ret = new LinkedList<String>();
		if (input == null) {
		return ret;
		}

		String[] strs = input.split(" ");

		float defautWeight = 5;

		// 当weight = -1，表示这一组食物-重量链还未完成
		String food = null;
		float weight = 0;

		// 记录某重量下所有的食物
		HashMap<Float, ArrayList<String>> map = new HashMap<Float, ArrayList<String>>();

		// Go through the string.
		for (String s: strs) {
		// 上一次的food-weight对已经结束
		if (weight != -1) {
		food = s;
		weight = -1;
		} else {
		float tmp = stringToNumber(s);
		// This is a float, so just add a food to the list.
		if (tmp != -1) {
		weight = tmp;
		addFoodToMap(map, food, weight);
		} else {
		// This is not a float, means that there should be
		// a new food.
		addFoodToMap(map, food, defautWeight);

		// 开始新一轮的食物-重量链
		food = s;
		weight = -1;
		}
		}
		}

		//System.out.println(map.toString());

		if (weight == -1) {
		addFoodToMap(map, food, defautWeight);
		}

		ArrayList<Float> array = new ArrayList<Float>(map.keySet());
		Collections.sort(array);

		for (Float w: array) {
		ArrayList<String> foods = map.get(w);
		for (String element: foods) {
		ret.addFirst(element);
		}
		}

		return ret;
		}

		public static void addFoodToMap(HashMap<Float, ArrayList<String>> map, String food,
		float weight) {
		// 把上一次的食物-重量终结
		ArrayList<String> list = map.get(weight);
		if (list != null) {
		// 在相应的重量下添加食物
		list.add(food);
		} else {
		// 新建一个重量链
		ArrayList<String> listNew = new ArrayList<String>();
		listNew.add(food);
		map.put(weight, listNew);
		}
		}

		// when it is not a float, return -1;
		public static float stringToNumber(String cur) {
		float result = -1;

		try {
		result = Float.parseFloat(cur);
		} catch (NumberFormatException e) {
		result = -1;
		}

		return result;
		}
		}
Original file line number	Diff line number	Diff line change
Expand Up		@@ -47,7 +47,7 @@ public int minDepthRec(TreeNode root) {
		把 null 设置为返回一个最大值，这样的话，如果出现空子树，它不会影响最小值。但是如果左
		右均为空，则应返回1（即是仅仅为根节点）

		而且这种做法更加合理。因为如果是空树，应该是无法到达才是。这时就应该将值设置为最大。
		而且这种做法更加合理。因为如果是空树，应该是无法到达才是。这时就应该将值设置为最大。
		* */
		publicintminDepthHelp(TreeNoderoot) {
		if (root ==null) {
Expand Down