Runtime: 440 ms (Top 73.2%) | Memory: 70.79 MB (Top 29.5%)

Author: AnasImloul

scripts/algorithms/L/Longest Arithmetic Subsequence/Longest Arithmetic Subsequence.java

@@ -1,21 +1,25 @@
-class Solution {
-    public int longestArithSeqLength(int[] nums) {
-      int len=nums.length;
-        HashMap<Integer,Integer>[] dp=new HashMap[len];
-        int maxvalue=1;
-        for(int i=0;i<len;i++){
-            int curr=nums[i];
-            dp[i]=new HashMap<>();
-            HashMap<Integer,Integer>currmap=dp[i];
-            for(int j=0;j<i;j++){
-                int diff=curr-nums[j];
-                 HashMap<Integer,Integer>prev=dp[j];
-                int newval=prev.getOrDefault(diff,0)+1;
-                currmap.put(diff,newval);
-                dp[i]=currmap;
-                maxvalue=Math.max(maxvalue,currmap.get(diff));
+// Runtime: 440 ms (Top 73.2%) | Memory: 70.79 MB (Top 29.5%)
+
+class Solution 
+{
+    public int longestArithSeqLength(int[] nums) 
+    {
+        int n = nums.length;
+        int longest = 0;
+        Map<Integer, Integer>[] dp = new HashMap[n];
+        
+        for (int i = 0; i < n; i++) 
+        {
+            dp[i] = new HashMap<>();
+            
+            for (int j = 0; j < i; j++) 
+            {
+                int diff = nums[i] - nums[j];
+                dp[i].put(diff, dp[j].getOrDefault(diff, 1) + 1);
+                longest = Math.max(longest, dp[i].get(diff));
             }
         }
-        return maxvalue+1;
+        
+        return longest;
     }
-}
+}