wordladder

fay111101 · fay111101 · commit 12e0fad21a30 · 2018-10-25T12:06:14.000+08:00
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/CombinationSum.java b/src/main/java/leetcode/dfsbfsbacktracing/CombinationSum.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 import java.util.ArrayList;
 import java.util.Arrays;
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/CombinationSum2.java b/src/main/java/leetcode/dfsbfsbacktracing/CombinationSum2.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 import java.util.ArrayList;
 import java.util.Arrays;
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/Combinations.java b/src/main/java/leetcode/dfsbfsbacktracing/Combinations.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 import java.util.ArrayList;
 
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/GenerateParentheses.java b/src/main/java/leetcode/dfsbfsbacktracing/GenerateParentheses.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 import java.util.ArrayList;
 
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/NQueens.java b/src/main/java/leetcode/dfsbfsbacktracing/NQueens.java
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/NQueens2.java b/src/main/java/leetcode/dfsbfsbacktracing/NQueens2.java
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/PermutationSequence.java b/src/main/java/leetcode/dfsbfsbacktracing/PermutationSequence.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 /**
  * Created by fay on 2017/12/15.
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/Permutations.java b/src/main/java/leetcode/dfsbfsbacktracing/Permutations.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 import java.util.ArrayList;
 import java.util.List;
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/Permutations2.java b/src/main/java/leetcode/dfsbfsbacktracing/Permutations2.java
@@ -1,9 +1,8 @@
 
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 import java.util.ArrayList;
 import java.util.HashSet;
-import java.util.List;
 
 /**
  * Created by fay on 2017/12/12.
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/Powxn.java b/src/main/java/leetcode/dfsbfsbacktracing/Powxn.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 public class Powxn {
     public double pow(double x, int n) {
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/RestoreIpAddress.java b/src/main/java/leetcode/dfsbfsbacktracing/RestoreIpAddress.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 import java.util.ArrayList;
 
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/Sqrtx.java b/src/main/java/leetcode/dfsbfsbacktracing/Sqrtx.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 /*
 Implementint sqrt(int x).
 Compute and return the square root of x.
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/Subset.java b/src/main/java/leetcode/dfsbfsbacktracing/Subset.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 import java.util.ArrayList;
 import java.util.Arrays;
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/Subset2.java b/src/main/java/leetcode/dfsbfsbacktracing/Subset2.java
@@ -1,4 +1,4 @@
-package leetcode.dfsbacktracing;
+package leetcode.dfsbfsbacktracing;
 
 import java.util.ArrayList;
 
diff --git a/src/main/java/leetcode/dfsbfsbacktracing/_126_WordLadder.java b/src/main/java/leetcode/dfsbfsbacktracing/_126_WordLadder.java
@@ -0,0 +1,48 @@
+package leetcode.dfsbfsbacktracing;
+
+import java.util.HashSet;
+import java.util.LinkedList;
+
+public class _126_WordLadder {
+
+    public int ladderLength(String start, String end, HashSet<String> dict) {
+        if (start == null || end == null || start.length() == 0 || end.length() == 0 || start.length() != end.length())
+            return 0;
+
+        LinkedList<String> wordQueue = new LinkedList<String>();
+        int level = 1; //the start string already count for 1
+        int curnum = 1;//the candidate num on current level
+        int nextnum = 0;//counter for next level
+
+        wordQueue.add(start);
+
+        while (!wordQueue.isEmpty()) {
+            String word = wordQueue.poll();
+            curnum--;
+
+            for (int i = 0; i < word.length(); i++) {
+                char[] wordunit = word.toCharArray();
+                for (char j = 'a'; j <= 'z'; j++) {
+                    wordunit[i] = j;
+                    String temp = new String(wordunit);
+
+                    if (temp.equals(end))
+                        return level + 1;
+                    if (dict.contains(temp)) {
+                        wordQueue.add(temp);
+                        nextnum++;
+                        dict.remove(temp);
+                    }
+                }
+            }
+
+            if (curnum == 0) {
+                curnum = nextnum;
+                nextnum = 0;
+                level++;
+            }
+        }
+
+        return 0;
+    }
+}
diff --git a/src/main/java/leetcode/sort/QuikSort.java b/src/main/java/leetcode/sort/QuikSort.java
@@ -1,6 +1,40 @@
 package leetcode.sort;
 
 public class QuikSort {
+
+
+    int partition0(int[] arr,int low,int high){
+        int base=arr[(low+high)/2];
+        int temp;
+
+        while(low<=high){
+            while(arr[low]<base){
+                low++;
+            }
+            while(arr[high]>base){
+                high--;
+            }
+
+            if(low<=high){
+                temp=arr[low];
+                arr[low]=arr[high];
+                arr[high]=temp;
+                low++;
+                high--;
+            }
+        }
+        return low;
+    }
+    void quickSort0(int[] array, int start, int end){
+        int index=partition0(array,start,end);
+        if(start<index-1){
+            quickSort0(array,start,index-1);
+        }
+        if(index<end){
+            quickSort0(array,index,end);
+        }
+    }
+
     /**
      * 原始算法 Hoare
      * 先把选定为pivot的元素放到最开始，然后设定指针low和指针high，high指针右移，low指针左移，
@@ -30,9 +64,10 @@ int partition(int[] arr, int low, int high) {
         return low;
     }
 
+
     /**
      * 改进算法 让基准位置最后入位！
-     *
+     * 记住
      * @param arr
      * @param low
      * @param high
@@ -57,7 +92,8 @@ int partition1(int[] arr, int low, int high) {
 
     int[] quickSort(int[] arr, int low, int high) {
         if (low < high) {
-            int base = partition1(arr, low, high);
+//            int base = partition1(arr, low, high);
+            int base = partition(arr, low, high);
             quickSort(arr, 0, base - 1);
             quickSort(arr, base + 1, high);
         }
@@ -66,6 +102,7 @@ int[] quickSort(int[] arr, int low, int high) {
     }
 
     /**
+     * 不记！
      *  设置两个指针 low和high
      * 先把选定为pivot的元素放到最后，然后设定指针low和指针high，low指针左移，
      * high指针右移，当两个指针相撞后停止移动。期间如果符合交换条件，两元素交换。最后把pivot元素放到中间。
@@ -93,22 +130,6 @@ int partition3(int arr[], int begin, int end) {
         return low;
     }
 
-
-    /**
-     * 快速排序
-     *
-     * @param array 待排序数组
-     * @param start 待排序子数组的起始索引
-     * @param end   待排序子数组的结束索引
-     */
-    public  void quickSort2(int[] array, int start, int end) {
-        if (start < end) {
-            int position = partition2(array, start, end);
-            quickSort2(array, start, position - 1);
-            quickSort2(array, position + 1, end);
-        }
-    }
-
     /**
      * 类似冒泡排序的思路，把比pivot大的元素“往下沉”，把比pivot小的元素“往上浮”。剑指offer
      * @return 返回pivot所在位置下标
@@ -137,6 +158,23 @@ public int  partition2(int arr[], int begin, int end) {
         return small + 1;
     }
 
+    /**
+     * 快速排序
+     *
+     * @param array 待排序数组
+     * @param start 待排序子数组的起始索引
+     * @param end   待排序子数组的结束索引
+     */
+    public  void quickSort2(int[] array, int start, int end) {
+        if (start < end) {
+            int position = partition2(array, start, end);
+            quickSort2(array, start, position - 1);
+            quickSort2(array, position + 1, end);
+        }
+    }
+
+
+
     private void swap(int[] arr, int index1, int index2) {
         int tmp = arr[index1];
         arr[index1] = arr[index2];
@@ -156,10 +194,12 @@ public static void printArray(int[] array) {
     }
 
     public static void main(String[] args) {
-        int[] arr = {49, 38, 65, 97, 76, 13, 27, 49};
+        int[] arr = {49, 38, 65, 97, 76, 13, 27, 49,-1,-3};
         QuikSort qs = new QuikSort();
-//        arr = qs.quickSort(arr, 0, arr.length - 1);
+
+//        qs.quickSort(arr, 0, arr.length - 1);
         qs.quickSort2(arr, 0, arr.length - 1);
+//        qs.quickSort0(arr, 0, arr.length - 1);
         for (int num : arr) {
             System.out.println(num);
 
diff --git a/src/main/java/offer/list/_57_DeleteDuplication.java b/src/main/java/offer/list/_57_DeleteDuplication.java
@@ -5,28 +5,27 @@
  * 例如，链表1->2->3->3->4->4->5 处理后为 1->2->5
  */
 public class _57_DeleteDuplication {
+
     public ListNode deleteDuplication(ListNode pHead)
     {
-        if(pHead==null){
-            return null;
-        }
-        ListNode head=new ListNode(-1);
-        ListNode tail=head;
-        tail.next=pHead;
-        ListNode cur=pHead;
-        while(cur!=null){
-            if(cur.next!=null&&(cur.next.val==cur.val)){
-                while(cur.next!=null&&cur.next.val==cur.val){
-                    cur=cur.next;
-                }
-                cur=cur.next;
-                tail.next=cur;
-            }else{
-                cur=cur.next;
-                tail=tail.next;
-            }
+        if (pHead == null || pHead.next == null) return pHead;
 
+        ListNode dummy = new ListNode(-1);
+        dummy.next = pHead;
+        ListNode curr = pHead;
+        ListNode pre = dummy;
+
+        while (curr != null) {
+            while (curr.next != null && curr.next.val == curr.val) {
+                curr = curr.next;
+            }
+            if (pre.next == curr) {
+                pre = pre.next;
+            } else {
+                pre.next = curr.next;
+            }
+            curr = curr.next;
         }
-        return head.next;
+        return dummy.next;
     }
 }
diff --git a/src/main/java/offer/list/_5_PrintListFromTailToHead.java b/src/main/java/offer/list/_5_PrintListFromTailToHead.java
@@ -38,4 +38,6 @@ public ArrayList<Integer> printListFromTailToHead2(ListNode listNode) {
         return arrayList;
     }
 
+
+
 }

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-package leetcode.dfsbacktracing;`
	`1`	`+package leetcode.dfsbfsbacktracing;`
`2`	`2`
`3`	`3`	`import java.util.ArrayList;`
`4`	`4`	`import java.util.Arrays;`