Added tasks 3330-3337

src/main/java/g3301_3400/s3330_find_the_original_typed_string_i/Solution.java

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+package g3301_3400.s3330_find_the_original_typed_string_i;
+
+// #Easy #String #2024_10_29_Time_1_ms_(96.13%)_Space_42_MB_(72.46%)
+
+public class Solution {
+    public int possibleStringCount(String word) {
+        int n = word.length();
+        int count = 1;
+        char pre = word.charAt(0);
+        int temp = 0;
+        for (int i = 1; i < n; i++) {
+            char ch = word.charAt(i);
+            if (ch == pre) {
+                temp++;
+            } else {
+                if (temp >= 1) {
+                    count += temp;
+                }
+                temp = 0;
+                pre = ch;
+            }
+        }
+        if (temp >= 1) {
+            count += temp;
+        }
+        return count;
+    }
+}

src/main/java/g3301_3400/s3330_find_the_original_typed_string_i/readme.md

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+3330\. Find the Original Typed String I
+
+Easy
+
+Alice is attempting to type a specific string on her computer. However, she tends to be clumsy and **may** press a key for too long, resulting in a character being typed **multiple** times.
+
+Although Alice tried to focus on her typing, she is aware that she may still have done this **at most** _once_.
+
+You are given a string `word`, which represents the **final** output displayed on Alice's screen.
+
+Return the total number of _possible_ original strings that Alice _might_ have intended to type.
+
+**Example 1:**
+
+**Input:** word = "abbcccc"
+
+**Output:** 5
+
+**Explanation:**
+
+The possible strings are: `"abbcccc"`, `"abbccc"`, `"abbcc"`, `"abbc"`, and `"abcccc"`.
+
+**Example 2:**
+
+**Input:** word = "abcd"
+
+**Output:** 1
+
+**Explanation:**
+
+The only possible string is `"abcd"`.
+
+**Example 3:**
+
+**Input:** word = "aaaa"
+
+**Output:** 4
+
+**Constraints:**
+
+*   `1 <= word.length <= 100`
+*   `word` consists only of lowercase English letters.

src/main/java/g3301_3400/s3331_find_subtree_sizes_after_changes/Solution.java

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+package g3301_3400.s3331_find_subtree_sizes_after_changes;
+
+// #Medium #Array #String #Hash_Table #Tree #Depth_First_Search
+// #2024_10_29_Time_166_ms_(52.73%)_Space_86.3_MB_(8.86%)
+
+import java.util.ArrayList;
+import java.util.HashMap;
+
+public class Solution {
+    private int[] finalAns;
+
+    public int[] findSubtreeSizes(int[] parent, String s) {
+        int n = parent.length;
+        char[] arr = s.toCharArray();
+        int[] newParent = new int[n];
+        finalAns = new int[n];
+        HashMap<Integer, ArrayList<Integer>> tree = new HashMap<>();
+
+        for (int i = 1; i < n; i++) {
+            int parentNode = parent[i];
+            newParent[i] = parentNode;
+            while (parentNode != -1) {
+                if (arr[parentNode] == arr[i]) {
+                    newParent[i] = parentNode;
+                    break;
+                }
+                parentNode = parent[parentNode];
+            }
+        }
+
+        for (int i = 1; i < n; i++) {
+            if (!tree.containsKey(newParent[i])) {
+                tree.put(newParent[i], new ArrayList<>());
+            }
+
+            tree.get(newParent[i]).add(i);
+        }
+
+        findNodes(0, tree);
+        return finalAns;
+    }
+
+    private int findNodes(int parent, HashMap<Integer, ArrayList<Integer>> tree) {
+        int count = 1;
+        if (tree.containsKey(parent)) {
+            for (int i : tree.get(parent)) {
+                count += findNodes(i, tree);
+            }
+        }
+        finalAns[parent] = count;
+        return count;
+    }
+}

src/main/java/g3301_3400/s3331_find_subtree_sizes_after_changes/readme.md

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+3331\. Find Subtree Sizes After Changes
+
+Medium
+
+You are given a tree rooted at node 0 that consists of `n` nodes numbered from `0` to `n - 1`. The tree is represented by an array `parent` of size `n`, where `parent[i]` is the parent of node `i`. Since node 0 is the root, `parent[0] == -1`.
+
+You are also given a string `s` of length `n`, where `s[i]` is the character assigned to node `i`.
+
+We make the following changes on the tree **one** time **simultaneously** for all nodes `x` from `1` to `n - 1`:
+
+*   Find the **closest** node `y` to node `x` such that `y` is an ancestor of `x`, and `s[x] == s[y]`.
+*   If node `y` does not exist, do nothing.
+*   Otherwise, **remove** the edge between `x` and its current parent and make node `y` the new parent of `x` by adding an edge between them.
+
+Return an array `answer` of size `n` where `answer[i]` is the **size** of the subtree rooted at node `i` in the **final** tree.
+
+A **subtree** of `treeName` is a tree consisting of a node in `treeName` and all of its descendants.
+
+**Example 1:**
+
+**Input:** parent = [-1,0,0,1,1,1], s = "abaabc"
+
+**Output:** [6,3,1,1,1,1]
+
+**Explanation:**
+
+![](https://assets.leetcode.com/uploads/2024/08/15/graphex1drawio.png)
+
+The parent of node 3 will change from node 1 to node 0.
+
+**Example 2:**
+
+**Input:** parent = [-1,0,4,0,1], s = "abbba"
+
+**Output:** [5,2,1,1,1]
+
+**Explanation:**
+
+![](https://assets.leetcode.com/uploads/2024/08/20/exgraph2drawio.png)
+
+The following changes will happen at the same time:
+
+*   The parent of node 4 will change from node 1 to node 0.
+*   The parent of node 2 will change from node 4 to node 1.
+
+**Constraints:**
+
+*   `n == parent.length == s.length`
+*   <code>1 <= n <= 10<sup>5</sup></code>
+*   `0 <= parent[i] <= n - 1` for all `i >= 1`.
+*   `parent[0] == -1`
+*   `parent` represents a valid tree.
+*   `s` consists only of lowercase English letters.

src/main/java/g3301_3400/s3332_maximum_points_tourist_can_earn/Solution.java

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+package g3301_3400.s3332_maximum_points_tourist_can_earn;
+
+// #Medium #Array #Dynamic_Programming #Matrix #2024_10_29_Time_53_ms_(100.00%)_Space_55_MB_(78.55%)
+
+public class Solution {
+    public int maxScore(int n, int k, int[][] stayScores, int[][] travelScores) {
+        // dp[day][city]
+        int[][] dp = new int[k + 1][n];
+        int result = 0;
+        for (int day = k - 1; day >= 0; day--) {
+            for (int city = 0; city < n; city++) {
+                int stayScore = stayScores[day][city] + dp[day + 1][city];
+                int travelScore = 0;
+                for (int nextCity = 0; nextCity < n; nextCity++) {
+                    int nextScore = travelScores[city][nextCity] + dp[day + 1][nextCity];
+                    travelScore = Math.max(nextScore, travelScore);
+                }
+                dp[day][city] = Math.max(stayScore, travelScore);
+                result = Math.max(dp[day][city], result);
+            }
+        }
+        return result;
+    }
+}

src/main/java/g3301_3400/s3332_maximum_points_tourist_can_earn/readme.md

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+3332\. Maximum Points Tourist Can Earn
+
+Medium
+
+You are given two integers, `n` and `k`, along with two 2D integer arrays, `stayScore` and `travelScore`.
+
+A tourist is visiting a country with `n` cities, where each city is **directly** connected to every other city. The tourist's journey consists of **exactly** `k` **0-indexed** days, and they can choose **any** city as their starting point.
+
+Each day, the tourist has two choices:
+
+*   **Stay in the current city**: If the tourist stays in their current city `curr` during day `i`, they will earn `stayScore[i][curr]` points.
+*   **Move to another city**: If the tourist moves from their current city `curr` to city `dest`, they will earn `travelScore[curr][dest]` points.
+
+Return the **maximum** possible points the tourist can earn.
+
+**Example 1:**
+
+**Input:** n = 2, k = 1, stayScore = [[2,3]], travelScore = [[0,2],[1,0]]
+
+**Output:** 3
+
+**Explanation:**
+
+The tourist earns the maximum number of points by starting in city 1 and staying in that city.
+
+**Example 2:**
+
+**Input:** n = 3, k = 2, stayScore = [[3,4,2],[2,1,2]], travelScore = [[0,2,1],[2,0,4],[3,2,0]]
+
+**Output:** 8
+
+**Explanation:**
+
+The tourist earns the maximum number of points by starting in city 1, staying in that city on day 0, and traveling to city 2 on day 1.
+
+**Constraints:**
+
+*   `1 <= n <= 200`
+*   `1 <= k <= 200`
+*   `n == travelScore.length == travelScore[i].length == stayScore[i].length`
+*   `k == stayScore.length`
+*   `1 <= stayScore[i][j] <= 100`
+*   `0 <= travelScore[i][j] <= 100`
+*   `travelScore[i][i] == 0`

src/main/java/g3301_3400/s3333_find_the_original_typed_string_ii/Solution.java

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+package g3301_3400.s3333_find_the_original_typed_string_ii;
+
+// #Hard #String #Dynamic_Programming #Prefix_Sum
+// #2024_10_29_Time_89_ms_(90.20%)_Space_55.6_MB_(40.38%)
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Solution {
+    private static final long MOD = (long) 1e9 + 7;
+
+    public int possibleStringCount(String word, int k) {
+        List<Integer> list = new ArrayList<>();
+        int n = word.length();
+        int i = 0;
+        while (i < n) {
+            int j = i + 1;
+            while (j < n && word.charAt(j) == word.charAt(j - 1)) {
+                j++;
+            }
+            list.add(j - i);
+            i = j;
+        }
+        int m = list.size();
+        long[] power = new long[m];
+        power[m - 1] = list.get(m - 1);
+        for (i = m - 2; i >= 0; i--) {
+            power[i] = (power[i + 1] * list.get(i)) % MOD;
+        }
+        if (m >= k) {
+            return (int) power[0];
+        }
+        long[][] dp = new long[m][k - m + 1];
+        for (i = 0; i < k - m + 1; i++) {
+            if (list.get(m - 1) + i + m > k) {
+                dp[m - 1][i] = list.get(m - 1) - (long) (k - m - i);
+            }
+        }
+        for (i = m - 2; i >= 0; i--) {
+            long sum = (dp[i + 1][k - m] * list.get(i)) % MOD;
+            for (int j = k - m; j >= 0; j--) {
+                sum += dp[i + 1][j];
+                if (j + list.get(i) > k - m) {
+                    sum = (sum - dp[i + 1][k - m] + MOD) % MOD;
+                } else {
+                    sum = (sum - dp[i + 1][j + list.get(i)] + MOD) % MOD;
+                }
+                dp[i][j] = sum;
+            }
+        }
+        return (int) dp[0][0];
+    }
+}

src/main/java/g3301_3400/s3333_find_the_original_typed_string_ii/readme.md

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+3333\. Find the Original Typed String II
+
+Hard
+
+Alice is attempting to type a specific string on her computer. However, she tends to be clumsy and **may** press a key for too long, resulting in a character being typed **multiple** times.
+
+You are given a string `word`, which represents the **final** output displayed on Alice's screen. You are also given a **positive** integer `k`.
+
+Return the total number of _possible_ original strings that Alice _might_ have intended to type, if she was trying to type a string of size **at least** `k`.
+
+Since the answer may be very large, return it **modulo** <code>10<sup>9</sup> + 7</code>.
+
+**Example 1:**
+
+**Input:** word = "aabbccdd", k = 7
+
+**Output:** 5
+
+**Explanation:**
+
+The possible strings are: `"aabbccdd"`, `"aabbccd"`, `"aabbcdd"`, `"aabccdd"`, and `"abbccdd"`.
+
+**Example 2:**
+
+**Input:** word = "aabbccdd", k = 8
+
+**Output:** 1
+
+**Explanation:**
+
+The only possible string is `"aabbccdd"`.
+
+**Example 3:**
+
+**Input:** word = "aaabbb", k = 3
+
+**Output:** 8
+
+**Constraints:**
+
+*   <code>1 <= word.length <= 5 * 10<sup>5</sup></code>
+*   `word` consists only of lowercase English letters.
+*   `1 <= k <= 2000`