Merge pull request doocs#256 from HendSame/master

feat:add solution for '0502','1117','1195'

Author: yanglbme

solution/0500-0599/0502.IPO/Solution.java

@@ -0,0 +1,38 @@
+class Solution {
+    /**
+     * 贪心算法
+     */
+    public int findMaximizedCapital(int k, int W, int[] Profits, int[] Capital) {
+        // 首先检查是否存在所有项目都可投资且初始资本 W >= max(Capital) 的情况。如果是，返回利润中前 k 个最大元素的和。
+        boolean speedUp = true;
+        for (int c : Capital) if (W < c) speedUp = false;
+        if (speedUp) {
+            PriorityQueue<Integer> heap = new PriorityQueue<>();
+            for (int p : Profits) {
+                heap.add(p);
+                if (heap.size() > k) heap.poll();
+            }
+            for (int h : heap) W += h;
+            return W;
+        }
+
+        int idx;
+        int n = Profits.length;
+        for (int i = 0; i < Math.min(k, n); ++i) {
+            idx = -1;
+            // 找到获取利润最多的项目
+            for (int j = 0; j < n; ++j) {
+                if (W >= Capital[j]) {
+                    if (idx == -1) idx = j;
+                    else if (Profits[idx] < Profits[j]) idx = j;
+                }
+            }
+            // 找不到合适的项目
+            if (idx == -1) break;
+            // 累计当前项目的利润到总利润中，并把当前项目标记为"不可用"（设置成最大整数）
+            W += Profits[idx];
+            Capital[idx] = Integer.MAX_VALUE;
+        }
+        return W;
+    }
+} 

solution/1100-1199/1117.Building H2O/Solution.java

@@ -0,0 +1,24 @@
+class H2O {
+
+    private Semaphore h = new Semaphore(2);
+    private Semaphore o = new Semaphore(0);
+    public H2O() {
+
+    }
+
+    public void hydrogen(Runnable releaseHydrogen) throws InterruptedException {
+
+        // releaseHydrogen.run() outputs "H". Do not change or remove this line.
+        h.acquire();
+        releaseHydrogen.run();
+        o.release();
+    }
+
+    public void oxygen(Runnable releaseOxygen) throws InterruptedException {
+
+        // releaseOxygen.run() outputs "O". Do not change or remove this line.
+        o.acquire(2);
+        releaseOxygen.run();
+        h.release(2);
+    }
+}

solution/1100-1199/1195.Fizz Buzz Multithreaded/Solution.java

@@ -0,0 +1,60 @@
+class FizzBuzz {
+    private int n;
+
+    public FizzBuzz(int n) {
+        this.n = n;
+    }
+
+    private Semaphore fSema = new Semaphore(0);
+    private Semaphore bSema = new Semaphore(0);
+    private Semaphore fbSema = new Semaphore(0);
+    private Semaphore nSema = new Semaphore(1);
+
+    // printFizz.run() outputs "fizz".
+    public void fizz(Runnable printFizz) throws InterruptedException {
+        for (int i = 3; i <= n; i = i + 3) {
+            if (i % 5 != 0) {
+                fSema.acquire();
+                printFizz.run();
+                nSema.release();
+            }
+        }
+    }
+
+    // printBuzz.run() outputs "buzz".
+    public void buzz(Runnable printBuzz) throws InterruptedException {
+        for (int i = 5; i <= n; i = i + 5) {
+            if (i % 3 != 0) {
+                bSema.acquire();
+                printBuzz.run();
+                nSema.release();
+            }
+        }
+    }
+
+    // printFizzBuzz.run() outputs "fizzbuzz".
+    public void fizzbuzz(Runnable printFizzBuzz) throws InterruptedException {
+        for (int i = 15; i <= n; i = i + 15) {
+            fbSema.acquire();
+            printFizzBuzz.run();
+            nSema.release();
+        }
+    }
+
+    // printNumber.accept(x) outputs "x", where x is an integer.
+    public void number(IntConsumer printNumber) throws InterruptedException {
+        for (int i = 1; i <= n; i++) {
+            nSema.acquire();
+            if (i % 3 == 0 && i % 5 == 0) {
+                fbSema.release();
+            } else if (i % 3 == 0) {
+                fSema.release();
+            } else if (i % 5 == 0) {
+                bSema.release();
+            } else {
+                printNumber.accept(i);
+                nSema.release();
+            }
+        }
+    }
+}