139,200,257,297,374

src/Main.java

@@ -8,8 +8,13 @@
 
 public class Main {
     public static void main(String[] args) {
-        Solution347 solution347 = new Solution347();
-        String s = "(a)())()";
-        List<String> list = solution347.removeInvalidParentheses(s);
+        Solution139 solution139 = new Solution139();
+        String s ="leetcode";
+        List<String> list = new ArrayList<>();
+        list.add("leet");
+        list.add("code");
+        if(solution139.wordBreak(s,list)){
+            System.out.println(1);
+        }
     }
 }

src/Solution139.java

@@ -0,0 +1,26 @@
+import java.util.List;
+
+/**
+ * Created by cuibowu on 2017/8/19.
+ */
+public class Solution139 {
+    public boolean wordBreak(String s, List<String> wordDict) {
+        boolean[] wordBreaker = new boolean[s.length() + 1];
+        wordBreaker[0] = true;
+        for (int i = 1; i <= s.length(); i++) {
+            for (String ss:
+                 wordDict) {
+                if(ss.length()<=i){
+                    if(wordBreaker[i-ss.length()]==true){
+                        if(s.substring(i-ss.length(),i).equals(ss)){
+                            wordBreaker[i]=true;
+                            break;
+                        }
+                    }
+                }
+            }
+        }
+        return wordBreaker[s.length()];
+    }
+
+}

src/Solution200.java

@@ -0,0 +1,29 @@
+
+/**
+ * Created by cuibowu on 2017/8/19.
+ */
+public class Solution200 {
+    public int numIslands(char[][] grid) {
+        int count =0;
+        if(grid.length==0) return 0;
+        for(int i = 0;i<grid.length;i++){
+            for(int j=0;j<grid[i].length;j++){
+                if(grid[i][j]=='1'){
+                    markIsland(i,j,grid);
+                    count++;
+                }
+            }
+        }
+        return count;
+    }
+    private void markIsland(int i, int j, char[][] grid){
+        if(i<0||j<0||i>=grid.length||j>=grid[0].length||grid[i][j]!='1')
+            return;
+        grid[i][j]='0';
+        markIsland(i-1,j,grid);
+        markIsland(i+1,j,grid);
+        markIsland(i,j-1,grid);
+        markIsland(i,j+1,grid);
+
+    }
+}

src/Solution257.java

@@ -0,0 +1,24 @@
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * Created by cuibowu on 2017/8/19.
+ */
+public class Solution257 {
+    public List<String> binaryTreePaths(TreeNode root) {
+        List<String> result = new LinkedList<>();
+        if(root!=null)
+            searchPath(root,result,"");
+        return result;
+    }
+
+    private void  searchPath(TreeNode root, List<String> result, String currentPath){
+        currentPath += root.val;
+        if(root.left==null&&root.right==null)
+            result.add(currentPath);
+        if(root.left!=null)
+            searchPath(root.left,result,currentPath+"->");
+        if(root.right!=null)
+            searchPath(root.right,result,currentPath+"->");
+    }
+}

src/Solution297.java

@@ -0,0 +1,57 @@
+/**
+ * Created by cuibowu on 2017/8/19.
+ */
+
+import java.util.StringTokenizer;
+
+/**
+ * Definition for a binary tree node.
+ * public class TreeNode {
+ * int val;
+ * TreeNode left;
+ * TreeNode right;
+ * TreeNode(int x) { val = x; }
+ * }
+ */
+public class Solution297 {
+
+    // Encodes a tree to a single string.
+    public String serialize(TreeNode root) {
+        StringBuilder serialized = new StringBuilder();
+        serializer(root,serialized);
+        return serialized.toString();
+
+    }
+
+    // Decodes your encoded data to tree.
+    public TreeNode deserialize(String data) {
+        StringTokenizer st = new StringTokenizer(data);
+        return deserializer(st);
+
+    }
+
+    private void serializer(TreeNode root, StringBuilder serialized){
+        if(root!=null){
+            serialized.append(root.val);
+            serialized.append(" ");
+            serializer(root.left,serialized);
+            serializer(root.right,serialized);
+        }
+        else
+            serialized.append("$ ");
+    }
+
+    private TreeNode deserializer(StringTokenizer st){
+        String val = st.nextToken();
+        if(val=="$")
+            return null;
+        TreeNode root = new TreeNode(Integer.parseInt(val));
+        root.left=deserializer(st);
+        root.right=deserializer(st);
+        return root;
+    }
+}
+
+// Your Codec object will be instantiated and called as such:
+// Codec codec = new Codec();
+// codec.deserialize(codec.serialize(root));

src/Solution374.java

@@ -0,0 +1,23 @@
+/**
+ * Created by cuibowu on 2017/8/18.
+ */
+public class Solution374 {
+    public int guessNumber(int n) {
+        int low = 1, high = n;
+        while (low <= high) {
+            int mid = low + (high - low) / 2;
+            if (guess(mid) == 0)
+                return mid;
+            else if (guess(mid) == -1) {
+                high = mid - 1;
+            } else if (guess(mid) == 1) {
+                low = mid + 1;
+            }
+        }
+        return -1;
+    }
+
+    int guess(int n){
+        return 0;
+    }
+}