Create largestDivisibleSubset.java

Author: Trmpsanjay

largestDivisibleSubset.java

@@ -0,0 +1,51 @@
+class Solution {
+    public List<Integer> largestDivisibleSubset(int[] nums) {
+        
+        /*
+        
+        Copied soln i haven't study dp
+        
+        The basic idea is like:
+
+1. Sort
+2. Find the length of longest subset
+3. Record the largest element of it.
+4. Do a loop from the largest element to nums[0], add every element belongs to the longest subset.
+        
+        
+        
+        */
+        
+        List<Integer> res = new ArrayList<Integer>();
+        if (nums == null || nums.length == 0)
+            return res;
+        Arrays.sort(nums);
+        int[] dp = new int[nums.length];
+        for(int i = 0; i < dp.length; i++){
+            dp[i] +=1;
+        }
+
+        for(int i = 0; i < nums.length; i++)
+            for(int j = 0; j <i ; j++){
+                if(nums[i] % nums[j] == 0)
+                    dp[i] = Math.max(dp[i], dp[j] +1);
+            }
+
+        int maxIndex = 0;
+        for (int i = 1; i < nums.length; i++)
+            maxIndex = dp[i] > dp[maxIndex]? i: maxIndex;
+
+        int temp = nums[maxIndex];
+        int curDp = dp[maxIndex];
+        for(int i = maxIndex; i>=0; i--){
+            if(temp % nums[i] == 0 && dp[maxIndex] - dp[i] <=1){
+                res.add(nums[i]);
+                temp = nums[i];
+                maxIndex = i;
+            }
+        }
+        Collections.sort(res);
+        return res;
+        
+    }
+}