add code

Author: ncdhz

code/481.神奇字符串.java

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+/*
+ * @lc app=leetcode.cn id=481 lang=java
+ *
+ * [481] 神奇字符串
+ */
+
+// @lc code=start
+class Solution {
+ public int magicalString(int n) {
+ if (n <= 3) {
+ return 1;
+ }
+ int[] ls = new int[n];
+ ls[2] = 2;
+ int i = 2;
+ int j = 3;
+ boolean isOne = true;
+ int sum = 1;
+ while(j < n) {
+ for (int k = 0; j < n && k < ls[i]; k++) {
+ if (isOne) {
+ sum++;
+ }
+ ls[j++] = isOne ? 1 : 2; 
+ }
+ isOne = !isOne;
+ i++;
+ }
+ return sum;
+ }
+}
+// @lc code=end
+

code/594.最长和谐子序列.java

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+import java.util.HashMap;
+import java.util.Map;
+
+/*
+ * @lc app=leetcode.cn id=594 lang=java
+ *
+ * [594] 最长和谐子序列
+ */
+
+// @lc code=start
+class Solution {
+ public int findLHS(int[] nums) {
+ Map<Integer, Integer> ns = new HashMap<>();
+ for (Integer n: nums) {
+ if (ns.containsKey(n)) {
+ ns.put(n, ns.get(n) + 1);
+ } else {
+ ns.put(n, 1);
+ }
+ }
+
+ int sum = 0;
+ for (Integer i: ns.keySet()) {
+ if (ns.containsKey(i + 1)) {
+ int j = ns.get(i) + ns.get(i + 1);
+ if (j > sum) {
+ sum = j;
+ }
+ }
+ }
+
+ return sum;
+ }
+}
+// @lc code=end
+