Create substringWithConc.java

substringWithConc.java

@@ -0,0 +1,40 @@
+class Solution {
+    public static List<Integer> findSubstring(String s, String[] words) {
+      int n = s.length();
+        int k = words.length;
+        int wordLength = words[0].length();
+        int substringSize = wordLength * k;
+        HashMap<String, Integer> wordCount = new HashMap<>();
+        for (String word : words) {
+            wordCount.put(word, wordCount.getOrDefault(word, 0) + 1);
+        }
+        List<Integer> arr = new ArrayList<>();
+        for (int i = 0; i < wordLength; i++) {
+            HashMap<String, Integer> wordMap = new HashMap<>(wordCount);
+            int right = i,  left = i;
+            int wordUsed = 0;
+            while (right <= n - wordLength) {
+                String sub = s.substring(right, right + wordLength);
+                if(left < right){
+                    while ( left < right && ((wordMap.containsKey(sub) && wordMap.get(sub) <= 0) || !wordMap.containsKey(sub) || right - left == substringSize)) {
+                        String leftSub = s.substring(left, left + wordLength);
+                        if (wordMap.containsKey(leftSub)) {
+                            wordMap.put(leftSub, wordMap.get(leftSub) + 1);
+                            wordUsed--;
+                        }
+                        left = left + wordLength;
+                    }
+                }
+                if (wordMap.containsKey(sub) && wordMap.get(sub) > 0) {
+                    wordMap.put(sub, wordMap.get(sub) - 1);
+                    wordUsed++;
+                }
+                right = right + wordLength;
+                if (wordUsed == k) {
+                    arr.add(left);
+                }
+            }
+        }
+        return arr;
+    }
+}