diff --git a/leetcode-1431/src/com/aen/leetcode/Solution.java b/leetcode-1431/src/com/aen/leetcode/Solution.java
new file mode 100644
index 0000000000000000000000000000000000000000..8eab221ca539342f1c520385fb0971899c75b903
--- /dev/null
+++ b/leetcode-1431/src/com/aen/leetcode/Solution.java
@@ -0,0 +1,28 @@
+package com.aen.leetcode;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午3:32
+ */
+public class Solution {
+    public List<Boolean> kidsWithCandies(int[] candies, int extraCandies) {
+        int max = 0;
+        int len = candies.length;
+        List<Boolean> candyList = new ArrayList<>();
+        for (int i = 0; i < len; ++i) {
+            max = Math.max(max, candies[i]);
+        }
+        for (int i = 0; i < len; ++i) {
+            candyList.add(candies[i] + extraCandies >= max);
+        }
+        return candyList;
+    }
+}
diff --git a/leetcode-1431/src/com/aen/leetcode/SolutionTest.java b/leetcode-1431/src/com/aen/leetcode/SolutionTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..a3902da3f2a85e5ea0825903dabc9510b87726c3
--- /dev/null
+++ b/leetcode-1431/src/com/aen/leetcode/SolutionTest.java
@@ -0,0 +1,19 @@
+package com.aen.leetcode;
+
+import java.util.List;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午3:39
+ */
+public class SolutionTest {
+    public static void main(String[] args) {
+        Solution solution = new Solution();
+        List<Boolean> booleanList = solution.kidsWithCandies(new int[]{2, 3, 5, 1, 3}, 3);
+        System.out.println(booleanList);
+    }
+}
diff --git a/leetcode-1470/src/com/aen/leetcode/Solution.java b/leetcode-1470/src/com/aen/leetcode/Solution.java
new file mode 100644
index 0000000000000000000000000000000000000000..e138b83ce00f26a512ebf648966fe55fe8652815
--- /dev/null
+++ b/leetcode-1470/src/com/aen/leetcode/Solution.java
@@ -0,0 +1,23 @@
+package com.aen.leetcode;
+
+/**
+ * Title: {@link Solution}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午3:06
+ */
+public class Solution {
+    public int[] shuffle(int[] nums, int n) {
+        int len = nums.length;
+        int[] ints = new int[len];
+        int j = 0;
+        for (int i = 0; i < n; ++i) {
+            ints[j] = nums[i];
+            ints[j + 1] = nums[i + n];
+            j += 2;
+        }
+        return ints;
+    }
+}
diff --git a/leetcode-1470/src/com/aen/leetcode/SolutionTest.java b/leetcode-1470/src/com/aen/leetcode/SolutionTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..07ebcb6102d32ab5b785f2a4244bdea017dfe331
--- /dev/null
+++ b/leetcode-1470/src/com/aen/leetcode/SolutionTest.java
@@ -0,0 +1,20 @@
+package com.aen.leetcode;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午3:30
+ */
+public class SolutionTest {
+    public static void main(String[] args) {
+        int[] s = new int[]{2, 5, 1, 3, 4, 7};
+        Solution solution = new Solution();
+        int[] shuffle = solution.shuffle(s, 3);
+        for (int i : shuffle) {
+            System.out.println(i);
+        }
+    }
+}
diff --git a/leetcode-1480/src/com/aen/leetcode/Solution.java b/leetcode-1480/src/com/aen/leetcode/Solution.java
new file mode 100644
index 0000000000000000000000000000000000000000..ef6f2b8dc9850ee7b56efcbef61efd49d6ec7cd2
--- /dev/null
+++ b/leetcode-1480/src/com/aen/leetcode/Solution.java
@@ -0,0 +1,23 @@
+package com.aen.leetcode;
+
+/**
+ * Title: {@link Solution}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午2:48
+ */
+public class Solution {
+
+    public int[] runningSum(int[] nums) {
+        int len = nums.length;
+        if (len <= 1){
+            return nums;
+        }
+        for (int i = 1; i < len; ++i) {
+            nums[i] += nums[i -1];
+        }
+        return nums;
+    }
+}
diff --git a/leetcode-1512/src/com/aen/leetcode/Solution.java b/leetcode-1512/src/com/aen/leetcode/Solution.java
new file mode 100644
index 0000000000000000000000000000000000000000..fea1b6145f6263f2b87984bfb4fe195799997ffc
--- /dev/null
+++ b/leetcode-1512/src/com/aen/leetcode/Solution.java
@@ -0,0 +1,53 @@
+package com.aen.leetcode;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午4:02
+ */
+public class Solution {
+    public int numIdenticalPairsOne(int[] nums) {
+        int len = nums.length;
+        int count = 0;
+        Map<Integer, Integer> map = new HashMap<>();
+        for (int i = 0; i < len; ++i) {
+            Integer integer = map.getOrDefault(nums[i], 0);
+            count += integer;
+            map.put(nums[i], integer + 1);
+
+        }
+        return count;
+    }
+
+    public int numIdenticalPairsTwo(int[] nums) {
+        int len = nums.length;
+        int count = 0;
+        for (int i = 0; i < len; ++i) {
+            for (int j = i + 1; j < len; ++j) {
+                if (nums[i] == nums[j]) {
+                    ++count;
+                }
+            }
+        }
+        return count;
+    }
+
+    public int numIdenticalPairsThree(int[] nums) {
+        int len = nums.length;
+        int count = 0;
+        int[] countArr = new int[100];
+        for (int i = 0; i < len; ++i) {
+            count += countArr[nums[i]];
+            ++countArr[nums[i]];
+        }
+        return count;
+    }
+
+
+}
diff --git a/leetcode-1512/src/com/aen/leetcode/SolutionTest.java b/leetcode-1512/src/com/aen/leetcode/SolutionTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..a3b8bca27eedb0d3caabc0b0e53a9d34e59e46dc
--- /dev/null
+++ b/leetcode-1512/src/com/aen/leetcode/SolutionTest.java
@@ -0,0 +1,17 @@
+package com.aen.leetcode;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午4:02
+ */
+public class SolutionTest {
+    public static void main(String[] args) {
+        Solution solution = new Solution();
+        int i = solution.numIdenticalPairsThree(new int[]{1,1,1,1});
+        System.out.println(i);
+    }
+}
diff --git a/leetcode-1603/src/com/aen/leetcode/ParkingSystem.java b/leetcode-1603/src/com/aen/leetcode/ParkingSystem.java
new file mode 100644
index 0000000000000000000000000000000000000000..4b1b35f17a54b0c8f76d5ff78bcfc146aea90630
--- /dev/null
+++ b/leetcode-1603/src/com/aen/leetcode/ParkingSystem.java
@@ -0,0 +1,66 @@
+package com.aen.leetcode;
+
+import java.util.Calendar;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午4:48
+ */
+public class ParkingSystem {
+    private Map<Integer, Integer> map = new HashMap<>();
+
+    private int big;
+    private int medium;
+    private int small;
+
+
+    public ParkingSystem(int big, int medium, int small) {
+//        map.put(1, big);
+//        map.put(2, medium);
+//        map.put(3, small);
+        this.big = big;
+        this.medium = medium;
+        this.small = small;
+    }
+
+    public boolean addCar(int carType) {
+        switch (carType) {
+            case 1:
+                if (big > 0) {
+                    --big;
+                    return true;
+                }
+                break;
+            case 2:
+                if (medium > 0) {
+                    --medium;
+                    return true;
+                }
+                break;
+            case 3:
+                if (small > 0) {
+                    --small;
+                    return true;
+                }
+                break;
+        }
+        return false;
+    }
+
+//    public boolean addCar(int carType) {
+//        Integer integer = map.get(carType);
+//        if (integer > 0) {
+//            map.put(carType, integer-1);
+//            return true;
+//        }
+//        return false;
+//    }
+
+
+}
diff --git a/leetcode-1603/src/com/aen/leetcode/ParkingSystemTest.java b/leetcode-1603/src/com/aen/leetcode/ParkingSystemTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..e66e6c793263ae6c6fb66f405bd3fb05447768f0
--- /dev/null
+++ b/leetcode-1603/src/com/aen/leetcode/ParkingSystemTest.java
@@ -0,0 +1,19 @@
+package com.aen.leetcode;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午4:53
+ */
+public class ParkingSystemTest {
+    public static void main(String[] args) {
+        ParkingSystem parkingSystem = new ParkingSystem(1,1,0);
+        System.out.println(parkingSystem.addCar(1));
+        System.out.println(parkingSystem.addCar(2));
+        System.out.println(parkingSystem.addCar(3));
+        System.out.println(parkingSystem.addCar(1));
+    }
+}
diff --git a/leetcode-771/src/com/aen/leetcode/Solution.java b/leetcode-771/src/com/aen/leetcode/Solution.java
new file mode 100644
index 0000000000000000000000000000000000000000..c7cba344a55964725d17ad43a5c45619f3a3416b
--- /dev/null
+++ b/leetcode-771/src/com/aen/leetcode/Solution.java
@@ -0,0 +1,40 @@
+package com.aen.leetcode;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Stack;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午5:08
+ */
+public class Solution {
+
+    private Map<Character, Integer> map = new HashMap<>();
+
+    public int numJewelsInStones(String J, String S) {
+        int slen = S.length();
+        int jlen = J.length();
+        int count = 0;
+        for (int i = 0; i < slen; ++i) {
+            char s = S.charAt(i);
+            for (int j = 0; j < jlen; ++j) {
+                if (s == J.charAt(j)) {
+                    count++;
+                }
+            }
+        }
+        return count;
+    }
+
+    public void getMap(String J) {
+        int len = J.length();
+        for (int i = 0; i < len; ++i) {
+            map.put(J.charAt(i), 1);
+        }
+    }
+}
diff --git a/leetcode-771/src/com/aen/leetcode/SolutionTest.java b/leetcode-771/src/com/aen/leetcode/SolutionTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..c368f131609f9452b76d20f1e49891824ee30789
--- /dev/null
+++ b/leetcode-771/src/com/aen/leetcode/SolutionTest.java
@@ -0,0 +1,18 @@
+package com.aen.leetcode;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午5:39
+ */
+public class SolutionTest {
+
+    public static void main(String[] args) {
+        Solution solution = new Solution();
+        int i = solution.numJewelsInStones("aA", "aAAbbbb");
+        System.out.println(i);
+    }
+}
diff --git a/leetcode-844/src/com/aen/leetcode/Solution.java b/leetcode-844/src/com/aen/leetcode/Solution.java
new file mode 100644
index 0000000000000000000000000000000000000000..48e039ab45d3c81a351fccc581e596f8fb2f2f09
--- /dev/null
+++ b/leetcode-844/src/com/aen/leetcode/Solution.java
@@ -0,0 +1,30 @@
+package com.aen.leetcode;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午2:03
+ */
+public class Solution {
+    public boolean backspaceCompare(String S, String T) {
+        return compare(S).equals(compare(T));
+    }
+
+    public String compare(String s) {
+        int len = s.length();
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < len; i++) {
+            if (s.charAt(i) != '#') {
+                sb.append(s.charAt(i));
+            } else {
+                if (sb.length() > 0) {
+                    sb.deleteCharAt(sb.length() - 1);
+                }
+            }
+        }
+        return sb.toString();
+    }
+}
diff --git a/leetcode-844/src/com/aen/leetcode/SolutionTest.java b/leetcode-844/src/com/aen/leetcode/SolutionTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..e42e09aa7104c05bc864fca74be7c29322b0a6e4
--- /dev/null
+++ b/leetcode-844/src/com/aen/leetcode/SolutionTest.java
@@ -0,0 +1,35 @@
+package com.aen.leetcode;
+
+/**
+ * Title: {@link com.aen.leetcode}
+ * Description:
+ *
+ * @author 谭 tmn
+ * @email AbelEthan@126.com
+ * @date 20-10-19 下午2:44
+ */
+public class SolutionTest {
+
+    public static void main(String[] args) {
+//        输入：S = "ab#c", T = "ad#c"
+//        输出：true
+//        解释：S 和 T 都会变成 “ac”。
+//
+//        输入：S = "ab##", T = "c#d#"
+//        输出：true
+//        解释：S 和 T 都会变成 “”。
+//
+//        输入：S = "a##c", T = "#a#c"
+//        输出：true
+//        解释：S 和 T 都会变成 “c”。
+//
+//        输入：S = "a#c", T = "b"
+//        输出：false
+//        解释：S 会变成 “c”，但 T 仍然是 “b”。
+        Solution solution = new Solution();
+        System.out.println(solution.backspaceCompare("ab#c", "ad#c"));
+        System.out.println(solution.backspaceCompare("ab##", "c#d#"));
+        System.out.println(solution.backspaceCompare("a##c", "#a#c"));
+        System.out.println(solution.backspaceCompare("a#c", "b"));
+    }
+}