343. 整数拆分

Author: w2xi

README.md

@@ -127,6 +127,7 @@
 |304|[二维区域和检索 - 矩阵不可变](https://leetcode.cn/problems/range-sum-query-2d-immutable/)|[JavaScript](./algorithms/range-sum-query-2d-immutable.js)|Medium|
 |328|[奇偶链表](https://leetcode.cn/problems/odd-even-linked-list/)|[JavaScript](./algorithms/odd-even-linked-list.js)|Medium|
 |332|[重新安排行程](https://leetcode.cn/problems/reconstruct-itinerary/)|[JavaScript](./algorithms/reconstruct-itinerary.js)|Hard|
+|343|[整数拆分](https://leetcode.cn/problems/integer-break/)|[JavaScript](./algorithms/integer-break.js)|Medium|
 |344|[反转字符串](https://leetcode-cn.com/problems/reverse-string/)|[JavaScript](./algorithms/reverse-string.js)|Easy|
 |347|[前 K 个高频元素](https://leetcode.cn/problems/top-k-frequent-elements/)|[JavaScript](./algorithms/top-k-frequent-elements.js)|Medium|
 |349|[两个数组的交集](https://leetcode-cn.com/problems/intersection-of-two-arrays/)|[JavaScript](./algorithms/intersection-of-two-arrays.js)|Easy|

algorithms/integer-break.js

@@ -0,0 +1,32 @@
+/**
+ * 343. 整数拆分
+ * @param {number} n
+ * @return {number}
+ */
+var integerBreak = function (n) {
+  const dp = Array(n + 1).fill(0);
+  dp[2] = 1;
+
+  for (let i = 3; i <= n; i++) {
+    for (let j = 1; j <= i >> 1; j++) {
+      dp[i] = Math.max(dp[i], (i - j) * j, dp[i - j] * j);
+    }
+  }
+
+  return dp[n];
+};
+
+// 贪心
+var integerBreak = function (n) {
+  if (n === 2) return 1;
+  if (n === 3) return 2;
+  if (n === 4) return 4;
+
+  let a = 1;
+  while (n > 4) {
+    n -= 3;
+    a *= 3;
+  }
+
+  return a * n;
+};