Added tasks 3295-3298

Author: javadev

src/main/java/g3201_3300/s3295_report_spam_message/Solution.java

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+package g3201_3300.s3295_report_spam_message;
+
+// #Medium #Array #String #Hash_Table #2024_09_24_Time_39_ms_(98.87%)_Space_85.4_MB_(9.13%)
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
+public class Solution {
+    public boolean reportSpam(String[] message, String[] bannedWords) {
+        Set<String> bannedUnique = new HashSet<>(Arrays.asList(bannedWords));
+        int bannedCount = 0;
+        for (String msg : message) {
+            if (bannedUnique.contains(msg)) {
+                bannedCount++;
+            }
+            if (bannedCount == 2) {
+                return true;
+            }
+        }
+        return false;
+    }
+}

src/main/java/g3201_3300/s3295_report_spam_message/readme.md

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+3295\. Report Spam Message
+
+Medium
+
+You are given an array of strings `message` and an array of strings `bannedWords`.
+
+An array of words is considered **spam** if there are **at least** two words in it that **exactly** match any word in `bannedWords`.
+
+Return `true` if the array `message` is spam, and `false` otherwise.
+
+**Example 1:**
+
+**Input:** message = ["hello","world","leetcode"], bannedWords = ["world","hello"]
+
+**Output:** true
+
+**Explanation:**
+
+The words `"hello"` and `"world"` from the `message` array both appear in the `bannedWords` array.
+
+**Example 2:**
+
+**Input:** message = ["hello","programming","fun"], bannedWords = ["world","programming","leetcode"]
+
+**Output:** false
+
+**Explanation:**
+
+Only one word from the `message` array (`"programming"`) appears in the `bannedWords` array.
+
+**Constraints:**
+
+*   <code>1 <= message.length, bannedWords.length <= 10<sup>5</sup></code>
+*   `1 <= message[i].length, bannedWords[i].length <= 15`
+*   `message[i]` and `bannedWords[i]` consist only of lowercase English letters.

src/main/java/g3201_3300/s3296_minimum_number_of_seconds_to_make_mountain_height_zero/Solution.java

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+package g3201_3300.s3296_minimum_number_of_seconds_to_make_mountain_height_zero;
+
+// #Medium #Array #Math #Binary_Search #2024_09_24_Time_6_ms_(100.00%)_Space_45.2_MB_(90.23%)
+
+public class Solution {
+    public long minNumberOfSeconds(int mountainHeight, int[] workerTimes) {
+        long left = 0;
+        long right = (long) mountainHeight * (mountainHeight + 1) / 2 * workerTimes[0];
+        while (left < right) {
+            long mid = left + (right - left) / 2;
+            if (canReduceMountain(workerTimes, mountainHeight, mid)) {
+                right = mid;
+            } else {
+                left = mid + 1;
+            }
+        }
+        return left;
+    }
+
+    private boolean canReduceMountain(int[] workerTimes, int mountainHeight, long timeLimit) {
+        long totalHeightReduced = 0;
+        for (int workerTime : workerTimes) {
+            long maxHeightThisWorker =
+                    (long) (Math.sqrt(2.0 * timeLimit / workerTime + 0.25) - 0.5);
+            totalHeightReduced += maxHeightThisWorker;
+            if (totalHeightReduced >= mountainHeight) {
+                return true;
+            }
+        }
+        return totalHeightReduced >= mountainHeight;
+    }
+}

src/main/java/g3201_3300/s3296_minimum_number_of_seconds_to_make_mountain_height_zero/readme.md

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+3296\. Minimum Number of Seconds to Make Mountain Height Zero
+
+Medium
+
+You are given an integer `mountainHeight` denoting the height of a mountain.
+
+You are also given an integer array `workerTimes` representing the work time of workers in **seconds**.
+
+The workers work **simultaneously** to **reduce** the height of the mountain. For worker `i`:
+
+*   To decrease the mountain's height by `x`, it takes `workerTimes[i] + workerTimes[i] * 2 + ... + workerTimes[i] * x` seconds. For example:
+    *   To reduce the height of the mountain by 1, it takes `workerTimes[i]` seconds.
+    *   To reduce the height of the mountain by 2, it takes `workerTimes[i] + workerTimes[i] * 2` seconds, and so on.
+
+Return an integer representing the **minimum** number of seconds required for the workers to make the height of the mountain 0.
+
+**Example 1:**
+
+**Input:** mountainHeight = 4, workerTimes = [2,1,1]
+
+**Output:** 3
+
+**Explanation:**
+
+One way the height of the mountain can be reduced to 0 is:
+
+*   Worker 0 reduces the height by 1, taking `workerTimes[0] = 2` seconds.
+*   Worker 1 reduces the height by 2, taking `workerTimes[1] + workerTimes[1] * 2 = 3` seconds.
+*   Worker 2 reduces the height by 1, taking `workerTimes[2] = 1` second.
+
+Since they work simultaneously, the minimum time needed is `max(2, 3, 1) = 3` seconds.
+
+**Example 2:**
+
+**Input:** mountainHeight = 10, workerTimes = [3,2,2,4]
+
+**Output:** 12
+
+**Explanation:**
+
+*   Worker 0 reduces the height by 2, taking `workerTimes[0] + workerTimes[0] * 2 = 9` seconds.
+*   Worker 1 reduces the height by 3, taking `workerTimes[1] + workerTimes[1] * 2 + workerTimes[1] * 3 = 12` seconds.
+*   Worker 2 reduces the height by 3, taking `workerTimes[2] + workerTimes[2] * 2 + workerTimes[2] * 3 = 12` seconds.
+*   Worker 3 reduces the height by 2, taking `workerTimes[3] + workerTimes[3] * 2 = 12` seconds.
+
+The number of seconds needed is `max(9, 12, 12, 12) = 12` seconds.
+
+**Example 3:**
+
+**Input:** mountainHeight = 5, workerTimes = [1]
+
+**Output:** 15
+
+**Explanation:**
+
+There is only one worker in this example, so the answer is `workerTimes[0] + workerTimes[0] * 2 + workerTimes[0] * 3 + workerTimes[0] * 4 + workerTimes[0] * 5 = 15`.
+
+**Constraints:**
+
+*   <code>1 <= mountainHeight <= 10<sup>5</sup></code>
+*   <code>1 <= workerTimes.length <= 10<sup>4</sup></code>
+*   <code>1 <= workerTimes[i] <= 10<sup>6</sup></code>

src/main/java/g3201_3300/s3297_count_substrings_that_can_be_rearranged_to_contain_a_string_i/Solution.java

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+package g3201_3300.s3297_count_substrings_that_can_be_rearranged_to_contain_a_string_i;
+
+// #Medium #String #Hash_Table #Sliding_Window #2024_09_24_Time_5_ms_(99.40%)_Space_44.9_MB_(51.04%)
+
+public class Solution {
+    public long validSubstringCount(String word1, String word2) {
+        long res = 0;
+        int keys = 0;
+        int len = word1.length();
+        int[] count = new int[26];
+        boolean[] letters = new boolean[26];
+        for (char letter : word2.toCharArray()) {
+            int index = letter - 'a';
+            if (count[index]++ == 0) {
+                letters[index] = true;
+                keys++;
+            }
+        }
+        int start = 0;
+        int end = 0;
+        while (end < len) {
+            int index = word1.charAt(end) - 'a';
+            if (!letters[index]) {
+                end++;
+                continue;
+            }
+            if (--count[index] == 0) {
+                --keys;
+            }
+            while (keys == 0) {
+                res += len - end;
+                int beginIndex = word1.charAt(start++) - 'a';
+                if (!letters[beginIndex]) {
+                    continue;
+                }
+                if (count[beginIndex]++ == 0) {
+                    keys++;
+                }
+            }
+            end++;
+        }
+        return res;
+    }
+}

src/main/java/g3201_3300/s3297_count_substrings_that_can_be_rearranged_to_contain_a_string_i/readme.md

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+3297\. Count Substrings That Can Be Rearranged to Contain a String I
+
+Medium
+
+You are given two strings `word1` and `word2`.
+
+A string `x` is called **valid** if `x` can be rearranged to have `word2` as a prefix.
+
+Return the total number of **valid** substrings of `word1`.
+
+**Example 1:**
+
+**Input:** word1 = "bcca", word2 = "abc"
+
+**Output:** 1
+
+**Explanation:**
+
+The only valid substring is `"bcca"` which can be rearranged to `"abcc"` having `"abc"` as a prefix.
+
+**Example 2:**
+
+**Input:** word1 = "abcabc", word2 = "abc"
+
+**Output:** 10
+
+**Explanation:**
+
+All the substrings except substrings of size 1 and size 2 are valid.
+
+**Example 3:**
+
+**Input:** word1 = "abcabc", word2 = "aaabc"
+
+**Output:** 0
+
+**Constraints:**
+
+*   <code>1 <= word1.length <= 10<sup>5</sup></code>
+*   <code>1 <= word2.length <= 10<sup>4</sup></code>
+*   `word1` and `word2` consist only of lowercase English letters.

src/main/java/g3201_3300/s3298_count_substrings_that_can_be_rearranged_to_contain_a_string_ii/Solution.java

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+package g3201_3300.s3298_count_substrings_that_can_be_rearranged_to_contain_a_string_ii;
+
+// #Hard #String #Hash_Table #Sliding_Window #2024_09_24_Time_31_ms_(100.00%)_Space_56.1_MB_(68.76%)
+
+public class Solution {
+    public long validSubstringCount(String word1, String word2) {
+        char[] ar = word1.toCharArray();
+        int n = ar.length;
+        char[] temp = word2.toCharArray();
+        int[] f = new int[26];
+        for (char i : temp) {
+            f[i - 97]++;
+        }
+        long ans = 0;
+        int needed = temp.length;
+        int beg = 0;
+        int end = 0;
+        while (end < n) {
+            if (f[ar[end] - 97]-- > 0) {
+                needed--;
+            }
+            while (needed == 0) {
+                // All substrings from [beg, i], where end <= i < n are valid
+                ans += n - end;
+                // Shrink
+                if (f[ar[beg++] - 97]++ == 0) {
+                    needed++;
+                }
+            }
+            end++;
+        }
+        return ans;
+    }
+}

src/main/java/g3201_3300/s3298_count_substrings_that_can_be_rearranged_to_contain_a_string_ii/readme.md

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+3298\. Count Substrings That Can Be Rearranged to Contain a String II
+
+Hard
+
+You are given two strings `word1` and `word2`.
+
+A string `x` is called **valid** if `x` can be rearranged to have `word2` as a prefix.
+
+Return the total number of **valid** substrings of `word1`.
+
+**Note** that the memory limits in this problem are **smaller** than usual, so you **must** implement a solution with a _linear_ runtime complexity.
+
+**Example 1:**
+
+**Input:** word1 = "bcca", word2 = "abc"
+
+**Output:** 1
+
+**Explanation:**
+
+The only valid substring is `"bcca"` which can be rearranged to `"abcc"` having `"abc"` as a prefix.
+
+**Example 2:**
+
+**Input:** word1 = "abcabc", word2 = "abc"
+
+**Output:** 10
+
+**Explanation:**
+
+All the substrings except substrings of size 1 and size 2 are valid.
+
+**Example 3:**
+
+**Input:** word1 = "abcabc", word2 = "aaabc"
+
+**Output:** 0
+
+**Constraints:**
+
+*   <code>1 <= word1.length <= 10<sup>6</sup></code>
+*   <code>1 <= word2.length <= 10<sup>4</sup></code>
+*   `word1` and `word2` consist only of lowercase English letters.

src/test/java/g3201_3300/s3295_report_spam_message/SolutionTest.java

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+package g3201_3300.s3295_report_spam_message;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class SolutionTest {
+    @Test
+    void reportSpam() {
+        assertThat(
+                new Solution()
+                        .reportSpam(
+                                new String[] {"hello", "world", "leetcode"},
+                                new String[] {"world", "hello"}),
+                equalTo(true));
+    }
+
+    @Test
+    void reportSpam2() {
+        assertThat(
+                new Solution()
+                        .reportSpam(
+                                new String[] {"hello", "programming", "fun"},
+                                new String[] {"world", "programming", "leetcode"}),
+                equalTo(false));
+    }
+}

src/test/java/g3201_3300/s3296_minimum_number_of_seconds_to_make_mountain_height_zero/SolutionTest.java

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+package g3201_3300.s3296_minimum_number_of_seconds_to_make_mountain_height_zero;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class SolutionTest {
+    @Test
+    void minNumberOfSeconds() {
+        assertThat(new Solution().minNumberOfSeconds(4, new int[] {2, 1, 1}), equalTo(3L));
+    }
+
+    @Test
+    void minNumberOfSeconds2() {
+        assertThat(new Solution().minNumberOfSeconds(10, new int[] {3, 2, 2, 4}), equalTo(12L));
+    }
+
+    @Test
+    void minNumberOfSeconds3() {
+        assertThat(new Solution().minNumberOfSeconds(5, new int[] {1}), equalTo(15L));
+    }
+}