update 315 java, readme, progress, code comment

yennanliu · Sep 7, 2024 · 06c047d · 06c047d
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diff --git a/README.md b/README.md
@@ -870,7 +870,7 @@
 275| [H-Index II](https://leetcode.com/problems/h-index-ii/) | [Python](./leetcode_python/Binary_Search/h-index-ii.py)  | _O(logn)_ | _O(1)_ | Medium |similar as `# 274 H-Index`, Binary Search, `fb` | AGAIN**** (3) 
 278| [First Bad Version](https://leetcode.com/problems/first-bad-version/) | [Python](./leetcode_python/Binary_Search/first-bad-version.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/BinarySearch/FirstBadVersion.java)| _O(logn)_ | _O(1)_ | Easy | `good basic`,LintCode, binary search, `fb` | OK*** (5) (MUST)
 300| [Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence/) | [Python](./leetcode_python/Binary_Search/longest-increasing-subsequence.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/BinarySearch/LongestIncreasingSubsequence.java)| _O(nlogn)_ | _O(n)_ | Medium |Curated Top 75, array, binary search,`DP good basic`, LintCode, DP,`amazon`,`fb`| AGAIN********** (10)
-315| [Count of Smaller Numbers After Self](https://leetcode.com/problems/count-of-smaller-numbers-after-self/description/) | [Python](./leetcode_python/Binary_Search/count_of_smaller_numbers_after_self.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/BinarySearch/countOfSmallerNumbersAfterSelf.java)| _O(logn)_ | _O(1)_ | Hard | binary search, BST, BIT,  `google` | again*
+315| [Count of Smaller Numbers After Self](https://leetcode.com/problems/count-of-smaller-numbers-after-self/description/) | [Python](./leetcode_python/Binary_Search/count_of_smaller_numbers_after_self.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/BinarySearch/CountOfSmallerNumbersAfterSelf.java)| _O(logn)_ | _O(1)_ | Hard | binary search, BST, BIT,  `google` | again*
 367| [Valid Perfect Square](https://leetcode.com/problems/valid-perfect-square/)| [Python](./leetcode_python/Binary_Search/valid-perfect-square.py),  [Java](./leetcode_java/src/main/java/LeetCodeJava/BinarySearch/ValidPerfectSquare.java)   | _O(logn)_  | _O(1)_| Easy | good basic, similar as `# 69 Sqrt(x)` | OK* (3)
 374| [Guess Number Higher or Lower](https://leetcode.com/problems/guess-number-higher-or-lower/)| [Python](./leetcode_python/Binary_Search/guess-number-higher-or-lower.py)| _O(logn)_ | _O(1)_| Easy| | OK*
 410| [Split Array Largest Sum](https://leetcode.com/problems/split-array-largest-sum/)| [Python](./leetcode_python/Binary_Search/split-array-largest-sum.py), [Java](./leetcode_java/src/main/java/LeetCodeJava/BinarySearch/SplitArrayLargestSum.java)| _O(logn)_| _O(1)_| Hard| google| AGAIN (not start)

diff --git a/data/progress.md b/data/progress.md
@@ -1,5 +1,8 @@
 # Progress
 
+# 2024-09-07
+- https://github.com/yennanliu/CS_basics/blob/master/doc/Leetcode_company_frequency-master/Google%206months-%20LeetCode.pdf
+
 # 2024-08-31
 - https://github.com/yennanliu/CS_basics/blob/master/doc/Leetcode_company_frequency-master/Google%206months-%20LeetCode.pdf
 

diff --git a/data/progress.txt b/data/progress.txt
@@ -1,3 +1,4 @@
+20240907: 315
 20240831: 1110, 1055
 20240824: 359,1057,1055(todo)
 20240810: 315

diff --git a/data/to_review.txt b/data/to_review.txt
@@ -1,11 +1,11 @@
 2024-10-25 -> ['1110, 1055']
 2024-10-18 -> ['359,1057,1055(todo)']
-2024-10-04 -> ['1110, 1055', '315']
+2024-10-04 -> ['315', '1110, 1055']
 2024-09-27 -> ['359,1057,1055(todo)']
 2024-09-21 -> ['1110, 1055']
 2024-09-15 -> ['809']
 2024-09-14 -> ['359,1057,1055(todo)']
-2024-09-13 -> ['1110, 1055', '315']
+2024-09-13 -> ['315', '1110, 1055']
 2024-09-08 -> ['1110, 1055']
 2024-09-06 -> ['359,1057,1055(todo)']
 2024-09-05 -> ['1110, 1055']

diff --git a/leetcode_java/src/main/java/LeetCodeJava/BinarySearch/CountOfSmallerNumbersAfterSelf.java b/leetcode_java/src/main/java/LeetCodeJava/BinarySearch/CountOfSmallerNumbersAfterSelf.java
@@ -4,7 +4,7 @@
 
 import java.util.*;
 
-public class countOfSmallerNumbersAfterSelf {
+public class CountOfSmallerNumbersAfterSelf {
 
     // V0
     // IDEA : BINARY SEARCH (fixed by GPT)
@@ -16,6 +16,13 @@ public List<Integer> countSmaller(int[] nums) {
         for (int i = nums.length - 1; i >= 0; i--) {
             int pos = findInsertPosition_(sortedList, nums[i]);
             res.add(pos);
+            /**
+             *  NOTE !!! insert op below
+             *
+             *  syntax :
+             *
+             *  public abstract void add(int index, E element )
+             */
             sortedList.add(pos, nums[i]);
         }
 
@@ -28,6 +35,29 @@ private int findInsertPosition_(List<Integer> sortedList, int target) {
         int left = 0;
         int right = sortedList.size();
 
+        /**
+         *  Log for below:
+         *
+         *   exp 1 : nums = [5,2,6,1]
+         *
+         *   sortedList = []
+         *   sortedList = [1]
+         *   sortedList = [1, 6]
+         *   sortedList = [1, 2, 6]
+         *
+         *
+         *   exp 2 :  nums = [-1]
+         *
+         *   sortedList = []
+         *
+         *
+         *  exp 3 :  nums = [-1,-1]
+         *
+         *   sortedList = []
+         *   sortedList = [-1]
+         */
+        System.out.println("sortedList = " + sortedList);
+
         while (left < right) {
             int mid = left + (right - left) / 2;
             if (sortedList.get(mid) >= target) {

diff --git a/leetcode_java/src/main/java/dev/workSpace4.java b/leetcode_java/src/main/java/dev/workSpace4.java
@@ -392,6 +392,20 @@ public int compare(Integer o1, Integer o2) {
         // >>> x_1 = [a, b]
         System.out.println(">>> x_1 = " + x_1.toString());
 
+        System.out.println("copyOfRange --------------");
+
+//        List<Integer> arr_100 = new ArrayList<>();
+//        arr_100.add(1);
+//        arr_100.add(2);
+//        arr_100.add(3);
+        int[] arr_100 = new int[]{1,2,3};
+        // int[] nums_ = Arrays.copyOfRange(nums, idx, nums.length);
+        //System.out.println(Arrays.copyOfRange(arr_100, 1, arr_100.length).toString());
+        int[] copy = Arrays.copyOfRange(arr_100, 1, arr_100.length);
+        for (int val : copy){
+            System.out.println(val);
+        }
+
 
     }
 

diff --git a/leetcode_java/src/main/java/dev/workspace3.java b/leetcode_java/src/main/java/dev/workspace3.java
@@ -6655,6 +6655,58 @@ private Map<String, Integer> getCountMap(String s){
     // LC 315
     // 6.28
     public List<Integer> countSmaller(int[] nums) {
+        List<Integer> res = new ArrayList<>();
+        if (nums == null || nums.length == 0){
+            return null;
+        }
+        if (nums.length == 1){
+            res.add(0);
+            return res;
+        }
+        // brute force
+        for (int i = 0; i < nums.length; i++){
+//            int cnt = 0;
+//            for (int j = i+1; j < nums.length; j++){
+//                if (nums[i] > nums[j]){
+//                    cnt += 1;
+//                }
+//            }
+//            res.add(cnt);
+            int cnt = findSmallerCnt(i, nums);
+            System.out.println(">>> cnt = " + cnt + ", i = " + i + " , nums = " + nums);
+            res.add(cnt);
+        }
+
+        return res;
+    }
+
+    private int findSmallerCnt(int idx, int[] nums){
+        int cnt = 0;
+        // binary search
+        int toCompare = nums[idx];
+        int[] nums_ = Arrays.copyOfRange(nums, idx+1, nums.length);
+        Arrays.sort(nums_);
+        int l = 0;
+        int r = nums_.length;
+        int mid = (l + r) / 2;
+        while (r > l){
+            System.out.println("l = " + l + ", r = " + r + ", mid = " + mid);
+            // found
+            if (toCompare < nums[mid+1] && toCompare > nums[mid-1]){
+                return nums_.length - mid;
+            }
+            if (toCompare > nums[mid]){
+                l = mid + 1;
+            }else{
+                r = mid;
+            }
+        }
+
+        return cnt;
+    }
+
+    ///////
+    public List<Integer> countSmaller_1(int[] nums) {
 
         List<Integer> res = new ArrayList<>();