weekly-237

Signed-off-by: ashKIK <[email protected]>

Author: px100

weekly-237/CheckIfTheSentenceIsPangram.java

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+import java.util.HashSet;
+import java.util.Set;
+
+// https://leetcode.com/contest/weekly-contest-237/problems/check-if-the-sentence-is-pangram/
+
+public class CheckIfTheSentenceIsPangram {
+
+  public boolean checkIfPangram(String sentence) {
+    Set<Character> set = new HashSet<>();
+    for (int i = 0; i < sentence.length(); i++) {
+      set.add(sentence.charAt(i));
+    }
+    return set.size() == 26;
+  }
+}

weekly-237/FindXORSumOfAllPairsBitwiseAND.java

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+
+// https://leetcode.com/contest/weekly-contest-237/problems/find-xor-sum-of-all-pairs-bitwise-and/
+
+public class FindXORSumOfAllPairsBitwiseAND {
+
+  // distributive property
+  // (a1^a2) & (b1^b2) = (a1&b1) ^ (a1&b2) ^ (a2&b1) ^ (a2&b2)
+  public int getXORSum(int[] arr1, int[] arr2) {
+    int xor1 = 0;
+    for (int val : arr1) {
+      xor1 ^= val;
+    }
+    int xor2 = 0;
+    for (int val : arr2) {
+      xor2 ^= val;
+    }
+    return xor1 & xor2;
+  }
+}

weekly-237/MaximumIceCreamBars.java

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+import java.util.Arrays;
+
+// https://leetcode.com/contest/weekly-contest-237/problems/maximum-ice-cream-bars/
+
+public class MaximumIceCreamBars {
+
+  public int maxIceCream(int[] costs, int coins) {
+    int totalCost = 0;
+    int iceCreams = 0;
+    Arrays.sort(costs);
+    for (int cost : costs) {
+      if (totalCost + cost <= coins) {
+        totalCost += cost;
+        iceCreams++;
+      }
+    }
+    return iceCreams;
+  }
+}

weekly-237/SingleThreadedCPU.java

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+import java.util.PriorityQueue;
+
+// https://leetcode.com/contest/weekly-contest-237/problems/single-threaded-cpu/
+
+public class SingleThreadedCPU {
+
+  // O(n*log(n))
+  public int[] getOrder(int[][] tasks) {
+    // Sort by enqueue time then by processing time
+    PriorityQueue<int[]> taskQueue = new PriorityQueue<>(
+        (a, b) -> a[0] == b[0] ? a[1] - b[1] : a[0] - b[0]);
+
+    // Sort by processing time then by id
+    PriorityQueue<int[]> waitQueue = new PriorityQueue<>(
+        (a, b) -> a[1] == b[1] ? a[2] - b[2] : a[1] - b[1]);
+
+    for (int i = 0; i < tasks.length; i++) {
+      taskQueue.offer(new int[]{tasks[i][0], tasks[i][1], i});
+    }
+
+    int[] result = new int[tasks.length];
+    int finishedTime = -1;
+    int idx = 0;
+
+    while (!taskQueue.isEmpty() || !waitQueue.isEmpty()) {
+      while (!taskQueue.isEmpty() && taskQueue.peek()[0] <= finishedTime) {
+        waitQueue.offer(taskQueue.poll());
+      }
+      int[] task;
+      if (!waitQueue.isEmpty()) {
+        task = waitQueue.poll();
+        finishedTime += task[1];
+      } else { // taskQueue is empty
+        task = taskQueue.poll();
+        finishedTime = task[0] + task[1];
+      }
+      result[idx++] = task[2];
+    }
+    return result;
+  }
+}

weekly-238/SumOfDigitsInBaseK.java

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+
+// https://leetcode.com/contest/weekly-contest-238/problems/sum-of-digits-in-base-k/
+
+import java.util.PriorityQueue;
+
+public class SumOfDigitsInBaseK {
+
+  public int sumBase(int n, int k) {
+    int sum = 0;
+    do {
+      sum += n % k;
+      n /= k;
+    } while (n != 0);
+    return sum;
+  }
+
+  public boolean checkZeroOnes(String s) {
+    char[] chr = s.toCharArray();
+    int ones = 0;
+    int mOne = 0;
+    int zeros = 0;
+    int mZero = 0;
+    for (char c : chr) {
+      if (c == '0') {
+        zeros++;
+        ones = 0;
+      } else {
+        ones++;
+        zeros = 0;
+      }
+      mOne = Math.max(mOne, ones);
+      mZero = Math.max(mZero, zeros);
+    }
+    return mOne > mZero;
+  }
+}