diff --git a/src/main/java/com/fancv/MyTest.java b/src/main/java/com/fancv/MyTest.java
new file mode 100644
index 0000000..adf26c9
--- /dev/null
+++ b/src/main/java/com/fancv/MyTest.java
@@ -0,0 +1,49 @@
+package com.fancv;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public class MyTest {
+    public static void main(String[] args) {
+        List<mydto> mydtoList= new ArrayList<>(2);
+        mydto a = new mydto();
+        a.setId(102L);
+        a.setName("a");
+
+        mydto b = new mydto();
+        b.setId(101L);
+        b.setName("a");
+        mydtoList.add(a);
+        mydtoList.add(b);
+
+        Map<String,Long> d =mydtoList.stream().collect(Collectors.toMap(mydto::getName,mydto::getId));
+    }
+
+}
+
+class mydto {
+
+    private String name;
+
+    private Long id;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+}
+
diff --git a/src/main/java/com/fancv/leetCode/String/LongestPalindrome_5.java b/src/main/java/com/fancv/leetCode/String/LongestPalindrome_5.java
new file mode 100644
index 0000000..358dfea
--- /dev/null
+++ b/src/main/java/com/fancv/leetCode/String/LongestPalindrome_5.java
@@ -0,0 +1,34 @@
+package com.fancv.leetCode.String;
+
+public class LongestPalindrome_5 {
+
+    public static void main(String[] args) {
+        System.out.println(longestPalindrome("cbbfddfddddffgdsgsdfgsdffffdddffffgsdfgsdgsdgsdff"));
+    }
+
+    public static String longestPalindrome(String s) {
+
+        int l = s.length();
+        String sub1 = null;
+        for (; l > 0; l--) {
+            for (int j = 0; j + l <= s.length(); j++) {
+                sub1 = s.substring(j, l + j);
+                if (isPalindromic(sub1)) {
+                    return sub1;
+                }
+            }
+        }
+        return null;
+    }
+
+    public static boolean isPalindromic(String s) {
+        int len = s.length();
+        for (int i = 0; i < len / 2; i++) {
+            if (s.charAt(i) != s.charAt(len - i - 1)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+}
diff --git a/src/main/java/com/fancv/leetCode/String/letterCombinations.java b/src/main/java/com/fancv/leetCode/String/letterCombinations.java
new file mode 100644
index 0000000..3780d47
--- /dev/null
+++ b/src/main/java/com/fancv/leetCode/String/letterCombinations.java
@@ -0,0 +1,79 @@
+package com.fancv.leetCode.String;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * 17 https://leetcode-cn.com/problems/letter-combinations-of-a-phone-number/
+ */
+public class letterCombinations {
+    public static List<String> letterCombinations(String digits) {
+        List<String> r = new ArrayList<>();
+        if (null == digits || digits.isEmpty()) {
+            return r;
+        }
+
+        Map<Character, String> h = new HashMap<>(16);
+        h.put('2', "abc");
+        h.put('3', "def");
+        h.put('4', "ghi");
+        h.put('5', "jkl");
+        h.put('6', "mno");
+        h.put('7', "pqrs");
+        h.put('8', "puv");
+        h.put('9', "wxyz");
+
+        if (digits.length() == 1) {
+            String t = h.get(digits.charAt(0));
+            for (char c : t.toCharArray()) {
+                r.add(Character.toString(c));
+            }
+            return r;
+        }
+        if (digits.length() == 2) {
+            for (char a1 : h.get(digits.charAt(0)).toCharArray()) {
+                for (char a2 : h.get(digits.charAt(1)).toCharArray()) {
+                    r.add(Character.toString(a1) + a2);
+                }
+            }
+
+            return r;
+        }
+        if (digits.length() == 3) {
+            for (char a1 : h.get(digits.charAt(0)).toCharArray()) {
+                for (char a2 : h.get(digits.charAt(1)).toCharArray()) {
+                    for (char a3 : h.get(digits.charAt(2)).toCharArray()) {
+                        r.add(Character.toString(a1) + a2+a3);
+                    }
+                }
+            }
+
+            return r;
+        }
+        if (digits.length() == 4) {
+            for (char a1 : h.get(digits.charAt(0)).toCharArray()) {
+                for (char a2 : h.get(digits.charAt(1)).toCharArray()) {
+                    for (char a3 : h.get(digits.charAt(2)).toCharArray()) {
+                        for (char a4 : h.get(digits.charAt(3)).toCharArray()) {
+                            r.add(Character.toString(a1) + a2+a3+a4);
+                        }
+                    }
+                }
+            }
+
+            return r;
+        }
+        return r;
+
+
+    }
+
+    public static void main(String[] args) {
+        String d = "23";
+
+        System.out.println(letterCombinations(d));
+    }
+
+}
diff --git a/src/main/java/com/fancv/leetCode/String/percentageLetter.java b/src/main/java/com/fancv/leetCode/String/percentageLetter.java
new file mode 100644
index 0000000..b6304d0
--- /dev/null
+++ b/src/main/java/com/fancv/leetCode/String/percentageLetter.java
@@ -0,0 +1,64 @@
+package com.fancv.leetCode.String;
+
+import java.text.DecimalFormat;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+
+public class percentageLetter {
+
+    public static int percentageLetter(String s, char letter) {
+
+        Long l =  s.chars().count();
+        Long q = s.chars().filter(c-> c==letter).count();
+
+        return (int)(100*(float)q/l);
+
+
+    }
+
+    public static void main(String[] args) {
+
+        Boolean s = wordPattern("abba","dog dog dog dog");
+        System.out.println(s);
+    }
+
+    public static boolean wordPattern(String pattern, String s) {
+
+        int[] p = pattern.chars().toArray();
+        String[] ss = s.split(" ");
+
+        if(p.length!=ss.length){
+            return false;
+        }
+
+        HashMap<Integer,String> map = new HashMap<>();
+        HashMap<String,Integer> map2 = new HashMap<>();
+
+        for(int i=0;i<p.length;i++){
+            String temp = map.get(p[i]);
+            Integer num = map2.get(ss[i]);
+            if (null==num){
+                map2.put(ss[i],p[i]);
+            }else {
+                if(num.equals(p[i])){
+                    continue;
+                }else {
+                    return false;
+                }
+            }
+
+            if(null==temp){
+                map.put(p[i],ss[i]);
+            }else{
+                if(temp.equals(ss[i])){
+                    continue;
+                }else {
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+}
diff --git a/src/main/java/com/fancv/leetCode/String/strStr.java b/src/main/java/com/fancv/leetCode/String/strStr.java
new file mode 100644
index 0000000..f43dbab
--- /dev/null
+++ b/src/main/java/com/fancv/leetCode/String/strStr.java
@@ -0,0 +1,74 @@
+package com.fancv.leetCode.String;
+
+import java.util.Stack;
+
+public class strStr {
+
+
+    public static int strStr(String haystack, String needle) {
+            if(haystack.contains(needle)){
+               return haystack.indexOf(needle);
+            }else {
+                return -1;
+            }
+
+    }
+
+    public static void main(String[] args) {
+     /*   System.out.println( strStr("hello","ll"));
+        System.out.println( strStr("",""));*/
+
+        System.out.println(calculate("1*5+12-3+9*1+856/80"));
+
+    }
+
+    /**
+     * 字符串计算机
+     * @param s
+     * @return
+     */
+    public  static int calculate(String s) {
+
+        s = s.replace(" ", "");
+        int l = s.length();
+        char[] chars = s.toCharArray();
+        Stack<Integer> stack = new Stack<>();
+        int num = 0;
+        char flag = '+';
+        for (int i = 0; i < l; i++) {
+            if (Character.isDigit(chars[i])) {
+                num = num * 10 + (chars[i]-'0');
+            }
+            if (!Character.isDigit(chars[i])  || i == s.length()-1) {
+                switch (flag) {
+                    case '+':
+                        stack.add(num);
+                        break;
+                    case '-':
+                        stack.add(-num);
+                        break;
+                    case '*':
+                        stack.add(stack.pop() * num);
+                        break;
+                    case '/':
+                        stack.add(stack.pop() / num);
+                        break;
+                }
+                flag = s.charAt(i);
+                num = 0;
+
+            }
+
+
+            }
+        num = 0;
+        while (!stack.empty()) {
+            num = num + stack.pop();
+        }
+
+        return num;
+    }
+
+
+
+}
diff --git a/src/main/java/com/fancv/leetCode/arrays/DivingBoard.java b/src/main/java/com/fancv/leetCode/arrays/DivingBoard.java
new file mode 100644
index 0000000..837946a
--- /dev/null
+++ b/src/main/java/com/fancv/leetCode/arrays/DivingBoard.java
@@ -0,0 +1,27 @@
+package com.fancv.leetCode.arrays;
+
+public class DivingBoard {
+
+    public static void main(String[] args) {
+
+        System.out.println(divingBoard(1, 1, 123));
+    }
+
+    public static int[] divingBoard(int shorter, int longer, int k) {
+
+
+        if (k == 0) {
+            return new int[k];
+        }
+        if (shorter == longer) {
+            return new int[]{shorter * k};
+        }
+        int[] r = new int[k + 1];
+        for (int i = 0; i < k + 1; i++) {
+
+            r[i] = shorter * (k - i) + longer * i;
+        }
+        return r;
+
+    }
+}
diff --git a/src/main/java/com/fancv/leetCode/arrays/GetIndex724.java b/src/main/java/com/fancv/leetCode/arrays/GetIndex724.java
new file mode 100644
index 0000000..8f85875
--- /dev/null
+++ b/src/main/java/com/fancv/leetCode/arrays/GetIndex724.java
@@ -0,0 +1,22 @@
+package com.fancv.leetCode.arrays;
+
+public class GetIndex724 {
+
+    public static void main(String[] args) {
+        System.out.println(pivotIndex(new int[]{2, 1 - 1}));
+    }
+
+    public static int pivotIndex(int[] nums) {
+        int total = nums.length;
+        int left = 0;
+        for (int i = 0; i < nums.length; i++) {
+
+            if (left * 2 == total - nums[i] && i != nums.length - 1) {
+                return i;
+            }
+            left = left + nums[i];
+
+        }
+        return -1;
+    }
+}
diff --git a/src/main/java/com/fancv/sort/bubbleSort.java b/src/main/java/com/fancv/sort/bubbleSort.java
index b49fc3c..020a661 100644
--- a/src/main/java/com/fancv/sort/bubbleSort.java
+++ b/src/main/java/com/fancv/sort/bubbleSort.java
@@ -3,6 +3,8 @@
 /**
  *冒泡排序
  *
+ * 双循环，每次最大的数据冒到最后边
+ * 复杂度 o(n2)
  * 外循环
  * 内循环
  *
@@ -11,7 +13,8 @@ public class bubbleSort {
 
     public static void main(String args[]) {
         System.out.println("冒泡排序");
-        int[] arr = {1, 9, 3, 2, 8, 4, 7};//创建数组
+
+        int[] arr = {91, 9, 3, 2, 8, 4, 7,4};//创建数组
         System.out.println("排序前");
         showArr(arr);//打印显示排序前
         //循环实现冒泡排序
@@ -24,6 +27,7 @@ public static void main(String args[]) {
                 }
 
             }
+            showArr(arr);
         }
         System.out.println("排序后");
         showArr(arr);
diff --git a/src/main/java/com/fancv/sort/newBubbleSort.java b/src/main/java/com/fancv/sort/newBubbleSort.java
new file mode 100644
index 0000000..88d2d01
--- /dev/null
+++ b/src/main/java/com/fancv/sort/newBubbleSort.java
@@ -0,0 +1,31 @@
+package com.fancv.sort;
+
+import java.util.Arrays;
+
+public class newBubbleSort {
+
+    public static void main(String[] args) {
+        System.out.println("盲写冒泡排序");
+
+        int[] list = {11, 3, 5, 4, 3, 2, 5, 67, 34, 23, 33};
+        sort(list);
+
+        System.out.println(Arrays.stream(list).toArray());
+
+    }
+
+    static void sort(int[] list) {
+
+        for (int i = 0; i < list.length - 1; i++) {
+            for (int j = 0; j < list.length - 1 - i; j++) {
+                if (list[j] > list[j + 1]) {
+                    int temp = list[j];
+                    list[j] = list[j + 1];
+                    list[j + 1] = temp;
+                }
+            }
+
+        }
+
+    }
+}
diff --git a/src/main/java/com/fancv/stocks/TradingVolume.java b/src/main/java/com/fancv/stocks/TradingVolume.java
new file mode 100644
index 0000000..0ef5bc2
--- /dev/null
+++ b/src/main/java/com/fancv/stocks/TradingVolume.java
@@ -0,0 +1,11 @@
+package com.fancv.stocks;
+
+/**
+ * 计算股票交易量
+ * 股票活跃度的指标
+ * 每天交易量的趋势
+ */
+public class TradingVolume {
+
+
+}
diff --git a/src/main/java/com/fancv/stringLight/ExcelNames_168.java b/src/main/java/com/fancv/stringLight/ExcelNames_168.java
new file mode 100644
index 0000000..e403be4
--- /dev/null
+++ b/src/main/java/com/fancv/stringLight/ExcelNames_168.java
@@ -0,0 +1,78 @@
+package com.fancv.stringLight;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class ExcelNames_168 {
+
+    public static void main(String[] args) {
+        System.out.println(convertToTitle(1));
+    }
+
+
+    public static String convertToTitle(int columnNumber) {
+
+        Map<Integer, String> integerStringMap = new HashMap<>(26);
+        integerStringMap.put(1, "A");
+        integerStringMap.put(2, "B");
+        integerStringMap.put(3, "C");
+        integerStringMap.put(4, "D");
+        integerStringMap.put(5, "E");
+        integerStringMap.put(6, "F");
+        integerStringMap.put(7, "G");
+        integerStringMap.put(8, "H");
+        integerStringMap.put(9, "I");
+        integerStringMap.put(10, "J");
+        integerStringMap.put(11, "K");
+        integerStringMap.put(12, "L");
+        integerStringMap.put(13, "M");
+        integerStringMap.put(14, "N");
+        integerStringMap.put(15, "O");
+        integerStringMap.put(16, "P");
+        integerStringMap.put(17, "Q");
+        integerStringMap.put(18, "R");
+        integerStringMap.put(19, "S");
+        integerStringMap.put(20, "T");
+        integerStringMap.put(21, "U");
+        integerStringMap.put(22, "V");
+        integerStringMap.put(23, "W");
+        integerStringMap.put(24, "X");
+        integerStringMap.put(25, "Y");
+        integerStringMap.put(26, "Z");
+
+        List<Integer> d = new ArrayList<>(24);
+        operation(columnNumber, d);
+
+        StringBuilder stringBuilder = new StringBuilder();
+        for (int i = d.size(); i > 0; i--) {
+            stringBuilder.append(integerStringMap.get(d.get(i - 1)));
+        }
+
+        return stringBuilder.toString();
+    }
+
+    public static void operation(int i, List<Integer> r) {
+        if (i > 26) {
+            int k = i % 26;
+            if (k == 0) {
+                r.add(26);
+                i = i-26;
+            } else {
+                r.add(k);
+            }
+            i = i / 26;
+            if (i > 26) {
+                operation(i, r);
+            } else {
+                r.add(i);
+            }
+
+        }else {
+            r.add(i);
+        }
+
+
+    }
+}
diff --git a/src/main/java/com/fancv/stringLight/LastWordLength_58.java b/src/main/java/com/fancv/stringLight/LastWordLength_58.java
new file mode 100644
index 0000000..e612bf8
--- /dev/null
+++ b/src/main/java/com/fancv/stringLight/LastWordLength_58.java
@@ -0,0 +1,51 @@
+package com.fancv.stringLight;
+
+import java.util.Arrays;
+
+public class LastWordLength_58 {
+
+    public static void main(String[] args) {
+        LastWordLength_58 lastWordLength_58 = new LastWordLength_58();
+
+        System.out.println(lastWordLength_58.lengthOfLastWord("dhfjd sdflka moon"));
+        System.out.println(lastWordLength_58.CheckPermutation("moongf ff", "mnff ofgo"));
+
+    }
+
+    public int lengthOfLastWord(String s) {
+        char[] chars = s.toCharArray();
+        int r = 0;
+        for (int j = chars.length; j > 0; j--) {
+            if (r == 0 && chars[j - 1] == 32) {
+                continue;
+            }
+            if (chars[j - 1] != 32) {
+                r++;
+            } else {
+                break;
+            }
+        }
+        return r;
+    }
+
+    public boolean CheckPermutation(String s1, String s2) {
+
+        char[] char1 = s1.toCharArray();
+        char[] char2 = s2.toCharArray();
+        if (char1.length != char2.length) {
+            return Boolean.FALSE;
+        }
+        Arrays.sort(char1);
+        Arrays.sort(char2);
+        for (int i = 0; i < char1.length; i++) {
+
+            if (char1[i] == char2[i]) {
+                continue;
+            } else {
+                return Boolean.FALSE;
+            }
+        }
+
+        return Boolean.TRUE;
+    }
+}