263:丑数

LeetCode/src/main/java/com/code/leet/week/LcpSolution.java

@@ -11,11 +11,11 @@ import java.util.stream.Collectors;
 public class LcpSolution {
     public static void main(String[] args) {
         LcpSolution solution = new LcpSolution();
-        System.out.println(solution.orchestraLayout(4, 1, 2));
+//        System.out.println(solution.orchestraLayout(4, 1, 2));
 
-//        int[] nums = {2, 2, 1, 9};
-//        int target = 10;
-//        System.out.println(solution.purchasePlans(nums, target));
+        int[] nums = {2, 2, 3, 5};
+        int target = 6;
+        System.out.println(solution.purchasePlans(nums, target));
     }
 
     public int magicTower(int[] nums) {
@@ -67,34 +67,56 @@ public class LcpSolution {
         return result % 9;
     }
 
+    //    public int purchasePlans(int[] nums, int target) {
+//        long count = 0;
+//        List<Integer> numList = Arrays.stream(nums).boxed().collect(Collectors.toList());
+//        Collections.sort(numList);
+//        Map<Integer, Long> map = new HashMap<>();
+//        int temp = -1;
+//        for (int num : numList) {
+//            if (num >= target) {
+//                break;
+//            }
+//            if (temp == -1) {
+//                for (int i = 1; i < num; i++) {
+//                    map.put(i, Long.parseLong("0"));
+//                }
+//                map.put(num, Long.parseLong("1"));
+//            } else {
+//                if (map.containsKey(target - num)) {
+//                    count += map.get(target - num);
+//                } else {
+//                    count += map.get(temp);
+//                }
+//                for (int i = temp + 1; i < num; i++) {
+//                    map.put(i, map.get(temp));
+//                }
+//                map.put(num, map.get(temp) + 1);
+//            }
+//            temp = num;
+//        }
+//        return (int) (count % (Math.pow(10, 9) + 7));
+//    }
     public int purchasePlans(int[] nums, int target) {
-        long count = 0;
-        List<Integer> numList = Arrays.stream(nums).boxed().collect(Collectors.toList());
-        Collections.sort(numList);
-        Map<Integer, Long> map = new HashMap<>();
-        int temp = -1;
-        for (int num : numList) {
-            if (num >= target) {
-                break;
-            }
-            if (temp == -1) {
-                for (int i = 1; i < num; i++) {
-                    map.put(i, Long.parseLong("0"));
-                }
-                map.put(num, Long.parseLong("1"));
-            } else {
-                if (map.containsKey(target - num)) {
-                    count += map.get(target - num);
-                } else {
-                    count += map.get(temp);
-                }
-                for (int i = temp + 1; i < num; i++) {
-                    map.put(i, map.get(temp));
-                }
-                map.put(num, map.get(temp) + 1);
-            }
-            temp = num;
-        }
-        return (int) (count % (Math.pow(10, 9) + 7));
+        int[] sort = new int[target];
+        long[] count = new long[target];
+        for (int num : nums) {
+            if (num < target) {
+                sort[num] += 1;
+            }
+        }
+        long sum = 0;
+        for (int i = 1; i < target; i++) {
+            sum += sort[i];
+            count[i] = sum;
+        }
+        long result = 0;
+        for (int num : nums) {
+            if (target > num) {
+                result += num <= target - num ? count[target - num] - 1 : count[target - num];
+            }
+        }
+        Calendar calendar = Calendar.getInstance();
+        return (int) (result / 2 % (Math.pow(10, 9) + 7));
     }
 }

LeetCode/src/main/java/leetcode/editor/cn/UglyNumber.java

@@ -0,0 +1,78 @@
+//给你一个整数 n ，请你判断 n 是否为 丑数 。如果是，返回 true ；否则，返回 false 。 
+//
+// 丑数 就是只包含质因数 2、3 和/或 5 的正整数。 
+//
+// 
+//
+// 示例 1： 
+//
+// 
+//输入：n = 6
+//输出：true
+//解释：6 = 2 × 3 
+//
+// 示例 2： 
+//
+// 
+//输入：n = 8
+//输出：true
+//解释：8 = 2 × 2 × 2
+// 
+//
+// 示例 3： 
+//
+// 
+//输入：n = 14
+//输出：false
+//解释：14 不是丑数，因为它包含了另外一个质因数 7 。
+// 
+//
+// 示例 4： 
+//
+// 
+//输入：n = 1
+//输出：true
+//解释：1 通常被视为丑数。
+// 
+//
+// 
+//
+// 提示： 
+//
+// 
+// -231 <= n <= 231 - 1 
+// 
+// Related Topics 数学 
+// 👍 221 👎 0
+
+package leetcode.editor.cn;
+
+//263:丑数
+public class UglyNumber {
+    public static void main(String[] args) {
+        //测试代码
+        Solution solution = new UglyNumber().new Solution();
+    }
+
+    //力扣代码
+    //leetcode submit region begin(Prohibit modification and deletion)
+    class Solution {
+        public boolean isUgly(int n) {
+            if (n <= 0) {
+                return false;
+            }
+            while (n % 5 == 0) {
+                n = n / 5;
+            }
+            while (n % 3 == 0) {
+                n = n / 3;
+            }
+            while (n % 2 == 0) {
+                n = n / 2;
+            }
+            return n == 1;
+        }
+    }
+//leetcode submit region end(Prohibit modification and deletion)
+
+}

LeetCode/src/main/java/leetcode/editor/cn/UglyNumber.md

@@ -0,0 +1,45 @@
+<p>给你一个整数 <code>n</code> ，请你判断 <code>n</code> 是否为 <strong>丑数</strong> 。如果是，返回 <code>true</code> ；否则，返回 <code>false</code> 。</p>
+
+<p><strong>丑数 </strong>就是只包含质因数 <code>2</code>、<code>3</code> 和/或 <code>5</code> 的正整数。</p>
+
+<p> </p>
+
+<p><strong>示例 1：</strong></p>
+
+<pre>
+<strong>输入：</strong>n = 6
+<strong>输出：</strong>true
+<strong>解释：</strong>6 = 2 × 3</pre>
+
+<p><strong>示例 2：</strong></p>
+
+<pre>
+<strong>输入：</strong>n = 8
+<strong>输出：</strong>true
+<strong>解释：</strong>8 = 2 × 2 × 2
+</pre>
+
+<p><strong>示例 3：</strong></p>
+
+<pre>
+<strong>输入：</strong>n = 14
+<strong>输出：</strong>false
+<strong>解释：</strong>14 不是丑数，因为它包含了另外一个质因数 <code>7 </code>。
+</pre>
+
+<p><strong>示例 4：</strong></p>
+
+<pre>
+<strong>输入：</strong>n = 1
+<strong>输出：</strong>true
+<strong>解释：</strong>1 通常被视为丑数。
+</pre>
+
+<p> </p>
+
+<p><strong>提示：</strong></p>
+
+<ul>
+	<li><code>-2<sup>31</sup> <= n <= 2<sup>31</sup> - 1</code></li>
+</ul>
+<div><div>Related Topics</div><div><li>数学</li></div></div>\n<div><li>👍 221</li><li>👎 0</li></div>