Added tasks 3174-3181

Author: javadev

src/main/kotlin/g3101_3200/s3174_clear_digits/Solution.kt

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+package g3101_3200.s3174_clear_digits
+
+// #Easy #String #Hash_Table #Simulation #2024_06_15_Time_180_ms_(70.18%)_Space_35.1_MB_(94.74%)
+
+class Solution {
+    fun clearDigits(s: String): String {
+        val result = StringBuilder()
+        for (ch in s.toCharArray()) {
+            if (ch in '0'..'9') {
+                if (result.isNotEmpty()) {
+                    result.deleteCharAt(result.length - 1)
+                }
+            } else {
+                result.append(ch)
+            }
+        }
+        return result.toString()
+    }
+}

src/main/kotlin/g3101_3200/s3174_clear_digits/readme.md

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+3174\. Clear Digits
+
+Easy
+
+You are given a string `s`.
+
+Your task is to remove **all** digits by doing this operation repeatedly:
+
+*   Delete the _first_ digit and the **closest** **non-digit** character to its _left_.
+
+Return the resulting string after removing all digits.
+
+**Example 1:**
+
+**Input:** s = "abc"
+
+**Output:** "abc"
+
+**Explanation:**
+
+There is no digit in the string.
+
+**Example 2:**
+
+**Input:** s = "cb34"
+
+**Output:** ""
+
+**Explanation:**
+
+First, we apply the operation on `s[2]`, and `s` becomes `"c4"`.
+
+Then we apply the operation on `s[1]`, and `s` becomes `""`.
+
+**Constraints:**
+
+*   `1 <= s.length <= 100`
+*   `s` consists only of lowercase English letters and digits.
+*   The input is generated such that it is possible to delete all digits.

src/main/kotlin/g3101_3200/s3175_find_the_first_player_to_win_k_games_in_a_row/Solution.kt

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+package g3101_3200.s3175_find_the_first_player_to_win_k_games_in_a_row
+
+// #Medium #Array #Simulation #2024_06_15_Time_536_ms_(100.00%)_Space_63.9_MB_(81.82%)
+
+class Solution {
+    fun findWinningPlayer(skills: IntArray, k: Int): Int {
+        val n = skills.size
+        var max = skills[0]
+        var cnt = 0
+        var res = 0
+        for (i in 1 until n) {
+            if (skills[i] > max) {
+                max = skills[i]
+                cnt = 0
+                res = i
+            }
+            cnt += 1
+            if (cnt == k) {
+                break
+            }
+        }
+        return res
+    }
+}

src/main/kotlin/g3101_3200/s3175_find_the_first_player_to_win_k_games_in_a_row/readme.md

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+3175\. Find The First Player to win K Games in a Row
+
+Medium
+
+A competition consists of `n` players numbered from `0` to `n - 1`.
+
+You are given an integer array `skills` of size `n` and a **positive** integer `k`, where `skills[i]` is the skill level of player `i`. All integers in `skills` are **unique**.
+
+All players are standing in a queue in order from player `0` to player `n - 1`.
+
+The competition process is as follows:
+
+*   The first two players in the queue play a game, and the player with the **higher** skill level wins.
+*   After the game, the winner stays at the beginning of the queue, and the loser goes to the end of it.
+
+The winner of the competition is the **first** player who wins `k` games **in a row**.
+
+Return the initial index of the _winning_ player.
+
+**Example 1:**
+
+**Input:** skills = [4,2,6,3,9], k = 2
+
+**Output:** 2
+
+**Explanation:**
+
+Initially, the queue of players is `[0,1,2,3,4]`. The following process happens:
+
+*   Players 0 and 1 play a game, since the skill of player 0 is higher than that of player 1, player 0 wins. The resulting queue is `[0,2,3,4,1]`.
+*   Players 0 and 2 play a game, since the skill of player 2 is higher than that of player 0, player 2 wins. The resulting queue is `[2,3,4,1,0]`.
+*   Players 2 and 3 play a game, since the skill of player 2 is higher than that of player 3, player 2 wins. The resulting queue is `[2,4,1,0,3]`.
+
+Player 2 won `k = 2` games in a row, so the winner is player 2.
+
+**Example 2:**
+
+**Input:** skills = [2,5,4], k = 3
+
+**Output:** 1
+
+**Explanation:**
+
+Initially, the queue of players is `[0,1,2]`. The following process happens:
+
+*   Players 0 and 1 play a game, since the skill of player 1 is higher than that of player 0, player 1 wins. The resulting queue is `[1,2,0]`.
+*   Players 1 and 2 play a game, since the skill of player 1 is higher than that of player 2, player 1 wins. The resulting queue is `[1,0,2]`.
+*   Players 1 and 0 play a game, since the skill of player 1 is higher than that of player 0, player 1 wins. The resulting queue is `[1,2,0]`.
+
+Player 1 won `k = 3` games in a row, so the winner is player 1.
+
+**Constraints:**
+
+*   `n == skills.length`
+*   <code>2 <= n <= 10<sup>5</sup></code>
+*   <code>1 <= k <= 10<sup>9</sup></code>
+*   <code>1 <= skills[i] <= 10<sup>6</sup></code>
+*   All integers in `skills` are unique.

src/main/kotlin/g3101_3200/s3176_find_the_maximum_length_of_a_good_subsequence_i/Solution.kt

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+package g3101_3200.s3176_find_the_maximum_length_of_a_good_subsequence_i
+
+// #Medium #Array #Hash_Table #Dynamic_Programming
+// #2024_06_15_Time_183_ms_(100.00%)_Space_37.6_MB_(91.30%)
+
+import kotlin.math.max
+
+class Solution {
+    fun maximumLength(nums: IntArray, k: Int): Int {
+        val n = nums.size
+        var count = 0
+        for (i in 0 until nums.size - 1) {
+            if (nums[i] != nums[i + 1]) {
+                count++
+            }
+        }
+        if (count <= k) {
+            return n
+        }
+        val max = IntArray(k + 1)
+        max.fill(1)
+        val vis = IntArray(n)
+        vis.fill(-1)
+        val map = HashMap<Int, Int>()
+        for (i in 0 until n) {
+            if (!map.containsKey(nums[i])) {
+                map[nums[i]] = i + 1
+            } else {
+                vis[i] = map[nums[i]]!! - 1
+                map[nums[i]] = i + 1
+            }
+        }
+        val dp = Array(n) { IntArray(k + 1) }
+        for (i in 0 until n) {
+            for (j in 0..k) {
+                dp[i][j] = 1
+            }
+        }
+        for (i in 1 until n) {
+            for (j in k - 1 downTo 0) {
+                dp[i][j + 1] = max(dp[i][j + 1], (1 + max[j]))
+                max[j + 1] = max(max[j + 1], dp[i][j + 1])
+            }
+            if (vis[i] != -1) {
+                val a = vis[i]
+                for (j in 0..k) {
+                    dp[i][j] = max(dp[i][j], (1 + dp[a][j]))
+                    max[j] = max(dp[i][j], max[j])
+                }
+            }
+        }
+        var ans = 1
+        for (i in 0..k) {
+            ans = max(ans, max[i])
+        }
+        return ans
+    }
+}

src/main/kotlin/g3101_3200/s3176_find_the_maximum_length_of_a_good_subsequence_i/readme.md

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+3176\. Find the Maximum Length of a Good Subsequence I
+
+Medium
+
+You are given an integer array `nums` and a **non-negative** integer `k`. A sequence of integers `seq` is called **good** if there are **at most** `k` indices `i` in the range `[0, seq.length - 2]` such that `seq[i] != seq[i + 1]`.
+
+Return the **maximum** possible length of a **good** subsequence of `nums`.
+
+**Example 1:**
+
+**Input:** nums = [1,2,1,1,3], k = 2
+
+**Output:** 4
+
+**Explanation:**
+
+The maximum length subsequence is <code>[<ins>1</ins>,<ins>2</ins>,<ins>1</ins>,<ins>1</ins>,3]</code>.
+
+**Example 2:**
+
+**Input:** nums = [1,2,3,4,5,1], k = 0
+
+**Output:** 2
+
+**Explanation:**
+
+The maximum length subsequence is <code>[<ins>1</ins>,2,3,4,5,<ins>1</ins>]</code>.
+
+**Constraints:**
+
+*   `1 <= nums.length <= 500`
+*   <code>1 <= nums[i] <= 10<sup>9</sup></code>
+*   `0 <= k <= min(nums.length, 25)`

src/main/kotlin/g3101_3200/s3177_find_the_maximum_length_of_a_good_subsequence_ii/Solution.kt

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+package g3101_3200.s3177_find_the_maximum_length_of_a_good_subsequence_ii
+
+// #Hard #Array #Hash_Table #Dynamic_Programming
+// #2024_06_15_Time_284_ms_(100.00%)_Space_40.3_MB_(100.00%)
+
+import kotlin.math.max
+
+class Solution {
+    fun maximumLength(nums: IntArray, k: Int): Int {
+        val hm = HashMap<Int, Int>()
+        val n = nums.size
+        val pre = IntArray(n)
+        for (i in 0 until n) {
+            pre[i] = hm.getOrDefault(nums[i], -1)
+            hm[nums[i]] = i
+        }
+        val dp = Array(k + 1) { IntArray(n) }
+        for (i in 0 until n) {
+            dp[0][i] = 1
+            if (pre[i] >= 0) {
+                dp[0][i] = dp[0][pre[i]] + 1
+            }
+        }
+        for (i in 1..k) {
+            var max = 0
+            for (j in 0 until n) {
+                if (pre[j] >= 0) {
+                    dp[i][j] = dp[i][pre[j]] + 1
+                }
+                dp[i][j] = max(dp[i][j], (max + 1))
+                max = max(max, dp[i - 1][j])
+            }
+        }
+        var max = 0
+        for (i in 0 until n) {
+            max = max(max, dp[k][i])
+        }
+        return max
+    }
+}

src/main/kotlin/g3101_3200/s3177_find_the_maximum_length_of_a_good_subsequence_ii/readme.md

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+3177\. Find the Maximum Length of a Good Subsequence II
+
+Hard
+
+You are given an integer array `nums` and a **non-negative** integer `k`. A sequence of integers `seq` is called **good** if there are **at most** `k` indices `i` in the range `[0, seq.length - 2]` such that `seq[i] != seq[i + 1]`.
+
+Return the **maximum** possible length of a **good** subsequence of `nums`.
+
+**Example 1:**
+
+**Input:** nums = [1,2,1,1,3], k = 2
+
+**Output:** 4
+
+**Explanation:**
+
+The maximum length subsequence is <code>[<ins>1</ins>,<ins>2</ins>,<ins>1</ins>,<ins>1</ins>,3]</code>.
+
+**Example 2:**
+
+**Input:** nums = [1,2,3,4,5,1], k = 0
+
+**Output:** 2
+
+**Explanation:**
+
+The maximum length subsequence is <code>[<ins>1</ins>,2,3,4,5,<ins>1</ins>]</code>.
+
+**Constraints:**
+
+*   <code>1 <= nums.length <= 5 * 10<sup>3</sup></code>
+*   <code>1 <= nums[i] <= 10<sup>9</sup></code>
+*   `0 <= k <= min(50, nums.length)`

src/main/kotlin/g3101_3200/s3178_find_the_child_who_has_the_ball_after_k_seconds/Solution.kt

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+package g3101_3200.s3178_find_the_child_who_has_the_ball_after_k_seconds
+
+// #Easy #Math #Simulation #2024_06_15_Time_136_ms_(82.35%)_Space_33.7_MB_(45.10%)
+
+class Solution {
+    fun numberOfChild(n: Int, k: Int): Int {
+        val bigN = 2 * n - 2
+        val x = k % bigN
+        return if (x < n) x else bigN - x
+    }
+}