longest-string-chain solution java

longest-string-chain/Solution.java

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+// Accepted
+// Runtime: 30 ms
+// Memory Usage: 39.1 MB
+// Submitted: January 14th, 2021
+
+class Solution {
+    public int longestStrChain(String[] words) {
+        Map<String, Integer> chain = new HashMap<String, Integer>();
+        
+        int longest = 0;
+        Arrays.sort(words, (a, b) -> a.length() - b.length());
+        
+        // Iterate from shortest to longest words, as previously sorted
+        for (String word : words) {
+            chain.put(word, 1); // 1 length chain default
+            
+            // Skip immediately, no 0 length words will ever be in input
+            if (word.length() == 1)
+                continue;
+            else {
+                for (int i = 0; i < word.length(); i++) {
+                    // Remove a char at once instance, and render the possible previous chain string
+                    StringBuilder sb = new StringBuilder(word);
+                    String test = sb.deleteCharAt(i).toString();
+                    
+                    // Check if the new chain we've found is larger than the last chain
+                    if (chain.containsKey(test) && chain.get(test) + 1 > chain.get(word))
+                        chain.put(word, chain.get(test) + 1);
+                }
+            }
+            
+            // Update answer if we've found a new longest chain
+            longest = Math.max(longest, chain.get(word));
+        }
+        
+        return longest;
+    }
+}