Skip to content

Added tasks 526-587 #23

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jan 30, 2023
Merged

Added tasks 526-587 #23

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
53 changes: 53 additions & 0 deletions README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,7 @@

| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0566 |[Reshape the Matrix](src/main/kotlin/g0501_0600/s0566_reshape_the_matrix)| Easy | Array, Matrix, Simulation | 239 | 99.05

#### Day 8 String

Expand Down Expand Up @@ -154,6 +155,7 @@
| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0503 |[Next Greater Element II](src/main/kotlin/g0501_0600/s0503_next_greater_element_ii)| Medium | Array, Stack, Monotonic_Stack | 331 | 92.68
| 0556 |[Next Greater Element III](src/main/kotlin/g0501_0600/s0556_next_greater_element_iii)| Medium | String, Math, Two_Pointers | 137 | 80.00

#### Day 11

Expand Down Expand Up @@ -245,6 +247,7 @@

| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0542 |[01 Matrix](src/main/kotlin/g0501_0600/s0542_01_matrix)| Medium | Array, Dynamic_Programming, Breadth_First_Search, Matrix | 441 | 94.06

#### Day 6 Matrix Related Problems

Expand All @@ -260,6 +263,7 @@

| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0547 |[Number of Provinces](src/main/kotlin/g0501_0600/s0547_number_of_provinces)| Medium | Depth_First_Search, Breadth_First_Search, Graph, Union_Find | 229 | 79.73

#### Day 9 Standard Traversal

Expand Down Expand Up @@ -300,6 +304,7 @@

| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0584 |[Find Customer Referee](src/main/kotlin/g0501_0600/s0584_find_customer_referee)| Easy | Database | 779 | 43.48
| 0183 |[Customers Who Never Order](src/main/kotlin/g0101_0200/s0183_customers_who_never_order)| Easy | Database | 712 | 33.67

#### Day 2 Select and Order
Expand Down Expand Up @@ -340,6 +345,7 @@

| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0586 |[Customer Placing the Largest Number of Orders](src/main/kotlin/g0501_0600/s0586_customer_placing_the_largest_number_of_orders)| Easy | LeetCode_Curated_SQL_70, Database | 768 | 44.85
| 0511 |[Game Play Analysis I](src/main/kotlin/g0501_0600/s0511_game_play_analysis_i)| Easy | LeetCode_Curated_SQL_70, Database | 790 | 45.04

#### Day 9 Control of Flow
Expand Down Expand Up @@ -582,6 +588,7 @@

| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0547 |[Number of Provinces](src/main/kotlin/g0501_0600/s0547_number_of_provinces)| Medium | Depth_First_Search, Breadth_First_Search, Graph, Union_Find | 229 | 79.73

#### Day 20 Brute Force/Backtracking

Expand Down Expand Up @@ -645,6 +652,7 @@
| 0448 |[Find All Numbers Disappeared in an Array](src/main/kotlin/g0401_0500/s0448_find_all_numbers_disappeared_in_an_array)| Easy | Array, Hash_Table | 394 | 100.00
| 0442 |[Find All Duplicates in an Array](src/main/kotlin/g0401_0500/s0442_find_all_duplicates_in_an_array)| Medium | Array, Hash_Table | 480 | 73.81
| 0041 |[First Missing Positive](src/main/kotlin/g0001_0100/s0041_first_missing_positive)| Hard | Top_100_Liked_Questions, Top_Interview_Questions, Array, Hash_Table | 345 | 100.00
| 0532 |[K-diff Pairs in an Array](src/main/kotlin/g0501_0600/s0532_k_diff_pairs_in_an_array)| Medium | Array, Hash_Table, Sorting, Binary_Search, Two_Pointers | 230 | 84.62
| 0456 |[132 Pattern](src/main/kotlin/g0401_0500/s0456_132_pattern)| Medium | Array, Binary_Search, Stack, Ordered_Set, Monotonic_Stack | 434 | 100.00
| 0239 |[Sliding Window Maximum](src/main/kotlin/g0201_0300/s0239_sliding_window_maximum)| Hard | Top_100_Liked_Questions, Top_Interview_Questions, Array, Heap_Priority_Queue, Sliding_Window, Queue, Monotonic_Queue | 1059 | 86.14

Expand Down Expand Up @@ -812,6 +820,7 @@

| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0566 |[Reshape the Matrix](src/main/kotlin/g0501_0600/s0566_reshape_the_matrix)| Easy | Array, Matrix, Simulation | 239 | 99.05
| 0118 |[Pascal's Triangle](src/main/kotlin/g0101_0200/s0118_pascals_triangle)| Easy | Top_Interview_Questions, Array, Dynamic_Programming | 277 | 33.22

#### Day 5 Array
Expand Down Expand Up @@ -1062,6 +1071,7 @@
| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0344 |[Reverse String](src/main/kotlin/g0301_0400/s0344_reverse_string)| Easy | Top_Interview_Questions, String, Two_Pointers, Recursion | 445 | 69.75
| 0557 |[Reverse Words in a String III](src/main/kotlin/g0501_0600/s0557_reverse_words_in_a_string_iii)| Easy | String, Two_Pointers | 215 | 98.10

#### Day 5 Two Pointers

Expand All @@ -1074,6 +1084,7 @@
| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0003 |[Longest Substring Without Repeating Characters](src/main/kotlin/g0001_0100/s0003_longest_substring_without_repeating_characters)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, String, Hash_Table, Sliding_Window | 258 | 91.09
| 0567 |[Permutation in String](src/main/kotlin/g0501_0600/s0567_permutation_in_string)| Medium | String, Hash_Table, Two_Pointers, Sliding_Window | 169 | 100.00

#### Day 7 Breadth First Search Depth First Search

Expand All @@ -1090,6 +1101,7 @@

| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0542 |[01 Matrix](src/main/kotlin/g0501_0600/s0542_01_matrix)| Medium | Array, Dynamic_Programming, Breadth_First_Search, Matrix | 441 | 94.06
| 0994 |[Rotting Oranges](src/main/kotlin/g0901_1000/s0994_rotting_oranges)| Medium | Array, Breadth_First_Search, Matrix | 308 | 57.93

#### Day 10 Recursion Backtracking
Expand Down Expand Up @@ -1170,12 +1182,14 @@
| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0200 |[Number of Islands](src/main/kotlin/g0101_0200/s0200_number_of_islands)| Medium | Top_100_Liked_Questions, Top_Interview_Questions, Array, Depth_First_Search, Breadth_First_Search, Matrix, Union_Find | 252 | 95.41
| 0547 |[Number of Provinces](src/main/kotlin/g0501_0600/s0547_number_of_provinces)| Medium | Depth_First_Search, Breadth_First_Search, Graph, Union_Find | 229 | 79.73

#### Day 7 Breadth First Search Depth First Search

| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0117 |[Populating Next Right Pointers in Each Node II](src/main/kotlin/g0101_0200/s0117_populating_next_right_pointers_in_each_node_ii)| Medium | Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Linked_List | 199 | 94.67
| 0572 |[Subtree of Another Tree](src/main/kotlin/g0501_0600/s0572_subtree_of_another_tree)| Easy | Depth_First_Search, Tree, Binary_Tree, Hash_Function, String_Matching | 214 | 92.39

#### Day 8 Breadth First Search Depth First Search

Expand Down Expand Up @@ -1245,6 +1259,7 @@
| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 1143 |[Longest Common Subsequence](src/main/kotlin/g1101_1200/s1143_longest_common_subsequence)| Medium | Top_100_Liked_Questions, String, Dynamic_Programming | 307 | 38.36
| 0583 |[Delete Operation for Two Strings](src/main/kotlin/g0501_0600/s0583_delete_operation_for_two_strings)| Medium | String, Dynamic_Programming | 197 | 100.00

#### Day 18 Dynamic Programming

Expand Down Expand Up @@ -1398,6 +1413,7 @@

| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0540 |[Single Element in a Sorted Array](src/main/kotlin/g0501_0600/s0540_single_element_in_a_sorted_array)| Medium | Array, Binary_Search | 274 | 86.67

#### Day 10

Expand All @@ -1423,6 +1439,7 @@
| <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- --> | <!-- -->
|-|-|-|-|-|-
| 0154 |[Find Minimum in Rotated Sorted Array II](src/main/kotlin/g0101_0200/s0154_find_minimum_in_rotated_sorted_array_ii)| Hard | Array, Binary_Search | 275 | 84.00
| 0528 |[Random Pick with Weight](src/main/kotlin/g0501_0600/s0528_random_pick_with_weight)| Medium | Math, Binary_Search, Prefix_Sum, Randomized | 393 | 91.38

#### Day 14

Expand Down Expand Up @@ -1613,8 +1630,44 @@
| 0763 |[Partition Labels](src/main/kotlin/g0701_0800/s0763_partition_labels)| Medium | Top_100_Liked_Questions, String, Hash_Table, Greedy, Two_Pointers, Data_Structure_II_Day_7_String | 235 | 84.75
| 0739 |[Daily Temperatures](src/main/kotlin/g0701_0800/s0739_daily_temperatures)| Medium | Top_100_Liked_Questions, Array, Stack, Monotonic_Stack, Programming_Skills_II_Day_6 | 936 | 80.54
| 0647 |[Palindromic Substrings](src/main/kotlin/g0601_0700/s0647_palindromic_substrings)| Medium | Top_100_Liked_Questions, String, Dynamic_Programming | 266 | 67.83
| 0587 |[Erect the Fence](src/main/kotlin/g0501_0600/s0587_erect_the_fence)| Hard | Array, Math, Geometry | 470 | 100.00
| 0586 |[Customer Placing the Largest Number of Orders](src/main/kotlin/g0501_0600/s0586_customer_placing_the_largest_number_of_orders)| Easy | LeetCode_Curated_SQL_70, Database, SQL_I_Day_8_Function | 768 | 44.85
| 0584 |[Find Customer Referee](src/main/kotlin/g0501_0600/s0584_find_customer_referee)| Easy | Database, SQL_I_Day_1_Select | 779 | 43.48
| 0583 |[Delete Operation for Two Strings](src/main/kotlin/g0501_0600/s0583_delete_operation_for_two_strings)| Medium | String, Dynamic_Programming, Algorithm_II_Day_17_Dynamic_Programming | 197 | 100.00
| 0581 |[Shortest Unsorted Continuous Subarray](src/main/kotlin/g0501_0600/s0581_shortest_unsorted_continuous_subarray)| Medium | Array, Sorting, Greedy, Two_Pointers, Stack, Monotonic_Stack | 246 | 100.00
| 0576 |[Out of Boundary Paths](src/main/kotlin/g0501_0600/s0576_out_of_boundary_paths)| Medium | Dynamic_Programming | 153 | 100.00
| 0575 |[Distribute Candies](src/main/kotlin/g0501_0600/s0575_distribute_candies)| Easy | Array, Hash_Table | 538 | 76.92
| 0572 |[Subtree of Another Tree](src/main/kotlin/g0501_0600/s0572_subtree_of_another_tree)| Easy | Depth_First_Search, Tree, Binary_Tree, Hash_Function, String_Matching, Algorithm_II_Day_7_Breadth_First_Search_Depth_First_Search | 214 | 92.39
| 0567 |[Permutation in String](src/main/kotlin/g0501_0600/s0567_permutation_in_string)| Medium | String, Hash_Table, Two_Pointers, Sliding_Window, Algorithm_I_Day_6_Sliding_Window | 169 | 100.00
| 0566 |[Reshape the Matrix](src/main/kotlin/g0501_0600/s0566_reshape_the_matrix)| Easy | Array, Matrix, Simulation, Data_Structure_I_Day_4_Array, Programming_Skills_I_Day_7_Array | 239 | 99.05
| 0565 |[Array Nesting](src/main/kotlin/g0501_0600/s0565_array_nesting)| Medium | Array, Depth_First_Search | 553 | 100.00
| 0564 |[Find the Closest Palindrome](src/main/kotlin/g0501_0600/s0564_find_the_closest_palindrome)| Hard | String, Math | 179 | 100.00
| 0563 |[Binary Tree Tilt](src/main/kotlin/g0501_0600/s0563_binary_tree_tilt)| Easy | Depth_First_Search, Tree, Binary_Tree | 197 | 100.00
| 0561 |[Array Partition](src/main/kotlin/g0501_0600/s0561_array_partition_i)| Easy | Array, Sorting, Greedy, Counting_Sort | 337 | 90.48
| 0560 |[Subarray Sum Equals K](src/main/kotlin/g0501_0600/s0560_subarray_sum_equals_k)| Medium | Top_100_Liked_Questions, Array, Hash_Table, Prefix_Sum, Data_Structure_II_Day_5_Array | 692 | 53.27
| 0559 |[Maximum Depth of N-ary Tree](src/main/kotlin/g0501_0600/s0559_maximum_depth_of_n_ary_tree)| Easy | Depth_First_Search, Breadth_First_Search, Tree | 196 | 100.00
| 0558 |[Logical OR of Two Binary Grids Represented as Quad-Trees](src/main/kotlin/g0501_0600/s0558_logical_or_of_two_binary_grids_represented_as_quad_trees)| Medium | Tree, Divide_and_Conquer | 268 | 100.00
| 0557 |[Reverse Words in a String III](src/main/kotlin/g0501_0600/s0557_reverse_words_in_a_string_iii)| Easy | String, Two_Pointers, Algorithm_I_Day_4_Two_Pointers | 215 | 98.10
| 0556 |[Next Greater Element III](src/main/kotlin/g0501_0600/s0556_next_greater_element_iii)| Medium | String, Math, Two_Pointers, Programming_Skills_II_Day_10 | 137 | 80.00
| 0554 |[Brick Wall](src/main/kotlin/g0501_0600/s0554_brick_wall)| Medium | Array, Hash_Table | 307 | 100.00
| 0553 |[Optimal Division](src/main/kotlin/g0501_0600/s0553_optimal_division)| Medium | Array, Dynamic_Programming, Math | 154 | 100.00
| 0552 |[Student Attendance Record II](src/main/kotlin/g0501_0600/s0552_student_attendance_record_ii)| Hard | Dynamic_Programming | 151 | 100.00
| 0551 |[Student Attendance Record I](src/main/kotlin/g0501_0600/s0551_student_attendance_record_i)| Easy | String | 151 | 95.00
| 0547 |[Number of Provinces](src/main/kotlin/g0501_0600/s0547_number_of_provinces)| Medium | Depth_First_Search, Breadth_First_Search, Graph, Union_Find, Algorithm_II_Day_6_Breadth_First_Search_Depth_First_Search, Graph_Theory_I_Day_8_Standard_Traversal, Level_2_Day_19_Union_Find | 229 | 79.73
| 0546 |[Remove Boxes](src/main/kotlin/g0501_0600/s0546_remove_boxes)| Hard | Array, Dynamic_Programming, Memoization | 283 | 100.00
| 0543 |[Diameter of Binary Tree](src/main/kotlin/g0501_0600/s0543_diameter_of_binary_tree)| Easy | Top_100_Liked_Questions, Depth_First_Search, Tree, Binary_Tree, Level_2_Day_7_Tree, Udemy_Tree_Stack_Queue | 307 | 43.93
| 0542 |[01 Matrix](src/main/kotlin/g0501_0600/s0542_01_matrix)| Medium | Array, Dynamic_Programming, Breadth_First_Search, Matrix, Algorithm_I_Day_9_Breadth_First_Search_Depth_First_Search, Graph_Theory_I_Day_5_Matrix_Related_Problems | 441 | 94.06
| 0541 |[Reverse String II](src/main/kotlin/g0501_0600/s0541_reverse_string_ii)| Easy | String, Two_Pointers | 200 | 83.33
| 0540 |[Single Element in a Sorted Array](src/main/kotlin/g0501_0600/s0540_single_element_in_a_sorted_array)| Medium | Array, Binary_Search, Binary_Search_II_Day_9 | 274 | 86.67
| 0539 |[Minimum Time Difference](src/main/kotlin/g0501_0600/s0539_minimum_time_difference)| Medium | Array, String, Math, Sorting | 183 | 100.00
| 0538 |[Convert BST to Greater Tree](src/main/kotlin/g0501_0600/s0538_convert_bst_to_greater_tree)| Medium | Depth_First_Search, Tree, Binary_Tree, Binary_Search_Tree | 252 | 77.78
| 0537 |[Complex Number Multiplication](src/main/kotlin/g0501_0600/s0537_complex_number_multiplication)| Medium | String, Math, Simulation | 171 | 75.00
| 0535 |[Encode and Decode TinyURL](src/main/kotlin/g0501_0600/s0535_encode_and_decode_tinyurl)| Medium | String, Hash_Table, Design, Hash_Function | 183 | 81.25
| 0532 |[K-diff Pairs in an Array](src/main/kotlin/g0501_0600/s0532_k_diff_pairs_in_an_array)| Medium | Array, Hash_Table, Sorting, Binary_Search, Two_Pointers, Udemy_Arrays | 230 | 84.62
| 0530 |[Minimum Absolute Difference in BST](src/main/kotlin/g0501_0600/s0530_minimum_absolute_difference_in_bst)| Easy | Depth_First_Search, Breadth_First_Search, Tree, Binary_Tree, Binary_Search_Tree | 209 | 86.96
| 0529 |[Minesweeper](src/main/kotlin/g0501_0600/s0529_minesweeper)| Medium | Array, Depth_First_Search, Breadth_First_Search, Matrix | 243 | 87.50
| 0528 |[Random Pick with Weight](src/main/kotlin/g0501_0600/s0528_random_pick_with_weight)| Medium | Math, Binary_Search, Prefix_Sum, Randomized, Binary_Search_II_Day_13 | 393 | 91.38
| 0526 |[Beautiful Arrangement](src/main/kotlin/g0501_0600/s0526_beautiful_arrangement)| Medium | Array, Dynamic_Programming, Bit_Manipulation, Backtracking, Bitmask | 107 | 100.00
| 0525 |[Contiguous Array](src/main/kotlin/g0501_0600/s0525_contiguous_array)| Medium | Array, Hash_Table, Prefix_Sum | 471 | 100.00
| 0524 |[Longest Word in Dictionary through Deleting](src/main/kotlin/g0501_0600/s0524_longest_word_in_dictionary_through_deleting)| Medium | Array, String, Sorting, Two_Pointers | 307 | 100.00
| 0523 |[Continuous Subarray Sum](src/main/kotlin/g0501_0600/s0523_continuous_subarray_sum)| Medium | Array, Hash_Table, Math, Prefix_Sum | 682 | 95.45
Expand Down
70 changes: 70 additions & 0 deletions src/main/kotlin/g0501_0600/s0526_beautiful_arrangement/readme.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,70 @@
[![](https://img.shields.io/github/stars/javadev/LeetCode-in-Kotlin?label=Stars&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin)
[![](https://img.shields.io/github/forks/javadev/LeetCode-in-Kotlin?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin/fork)

## 526\. Beautiful Arrangement

Medium

Suppose you have `n` integers labeled `1` through `n`. A permutation of those `n` integers `perm` (**1-indexed**) is considered a **beautiful arrangement** if for every `i` (`1 <= i <= n`), **either** of the following is true:

* `perm[i]` is divisible by `i`.
* `i` is divisible by `perm[i]`.

Given an integer `n`, return _the **number** of the **beautiful arrangements** that you can construct_.

**Example 1:**

**Input:** n = 2

**Output:** 2

**Explanation:**

The first beautiful arrangement is [1,2]:

- perm[1] = 1 is divisible by i = 1

- perm[2] = 2 is divisible by i = 2

The second beautiful arrangement is [2,1]:

- perm[1] = 2 is divisible by i = 1

- i = 2 is divisible by perm[2] = 1

**Example 2:**

**Input:** n = 1

**Output:** 1

**Constraints:**

* `1 <= n <= 15`

## Solution

```kotlin
class Solution {
fun countArrangement(n: Int): Int {
return backtrack(n, n, arrayOfNulls(1 shl n + 1), 0)
}

private fun backtrack(n: Int, index: Int, cache: Array<Int?>, cacheindex: Int): Int {
if (index == 0) {
return 1
}
var result = 0
if (cache[cacheindex] != null) {
return cache[cacheindex]!!
}
for (i in n downTo 1) {
if (cacheindex and (1 shl i) == 0 && (i % index == 0 || index % i == 0)) {
result += backtrack(n, index - 1, cache, cacheindex or (1 shl i))
}
}
cache[cacheindex] = result
return result
}
}
```
91 changes: 91 additions & 0 deletions src/main/kotlin/g0501_0600/s0528_random_pick_with_weight/readme.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,91 @@
[![](https://img.shields.io/github/stars/javadev/LeetCode-in-Kotlin?label=Stars&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin)
[![](https://img.shields.io/github/forks/javadev/LeetCode-in-Kotlin?label=Fork%20me%20on%20GitHub%20&style=flat-square)](https://github.com/javadev/LeetCode-in-Kotlin/fork)

## 528\. Random Pick with Weight

Medium

You are given a **0-indexed** array of positive integers `w` where `w[i]` describes the **weight** of the <code>i<sup>th</sup></code> index.

You need to implement the function `pickIndex()`, which **randomly** picks an index in the range `[0, w.length - 1]` (**inclusive**) and returns it. The **probability** of picking an index `i` is `w[i] / sum(w)`.

* For example, if `w = [1, 3]`, the probability of picking index `0` is `1 / (1 + 3) = 0.25` (i.e., `25%`), and the probability of picking index `1` is `3 / (1 + 3) = 0.75` (i.e., `75%`).

**Example 1:**

**Input** ["Solution","pickIndex"] [[[1]],[]]

**Output:** [null,0]

**Explanation:**

Solution solution = new Solution([1]);
solution.pickIndex(); // return 0. The only option is to return 0 since there is only one element in w.

**Example 2:**

**Input**

["Solution","pickIndex","pickIndex","pickIndex","pickIndex","pickIndex"]
[[[1,3]],[],[],[],[],[]]

**Output:** [null,1,1,1,1,0]

**Explanation:**

Solution solution = new Solution([1, 3]);
solution.pickIndex(); // return 1. It is returning the second element (index = 1) that has a probability of 3/4.
solution.pickIndex(); // return 1
solution.pickIndex(); // return 1
solution.pickIndex(); // return 1
solution.pickIndex(); // return 0. It is returning the first element (index = 0) that has a probability of 1/4.

Since this is a randomization problem, multiple answers are allowed.
All of the following outputs can be considered correct:
[null,1,1,1,1,0]
[null,1,1,1,1,1]
[null,1,1,1,0,0]
[null,1,1,1,0,1]
[null,1,0,1,0,0]
......
and so on.

**Constraints:**

* <code>1 <= w.length <= 10<sup>4</sup></code>
* <code>1 <= w[i] <= 10<sup>5</sup></code>
* `pickIndex` will be called at most <code>10<sup>4</sup></code> times.

## Solution

```kotlin
import java.util.Random
import java.util.TreeMap

@Suppress("kotlin:S2245")
class Solution(val w: IntArray) {

var x: IntArray = IntArray(w.size) { 0 }
val rand = Random()
val tree = TreeMap<Int, Int>()
var sum = 0

init {
for (i in w.indices) {
tree.put(sum, i)
sum += w[i]
}
}

fun pickIndex(): Int {
val r = rand.nextInt(sum)
return tree.floorEntry(r).value!!
}
}

/*
* Your Solution object will be instantiated and called as such:
* var obj = Solution(w)
* var param_1 = obj.pickIndex()
*/
```
Loading