Create 438-Find-All-Anagrams-In-A-String.kt

Author: a93a

kotlin/438-Find-All-Anagrams-In-A-String.kt

@@ -0,0 +1,31 @@
+class Solution {
+    fun findAnagrams(s: String, p: String): List<Int> {
+        
+        val pCount = IntArray(26)
+        val res = ArrayList<Int>()
+        
+        for(c in p)
+            pCount[c - 'a']++
+        
+        var start = 0
+        var end = 0
+        
+        while(end < s.length){
+            // increase the window
+            if(pCount[s[end] - 'a'] > 0){
+                pCount[s[end++] - 'a']--
+                if(end-start == p.length)
+                    res.add(start)
+            // window size 0? step to next
+            }else if(start == end){
+                start++
+                end++
+            //decrease the window
+            }else{
+                pCount[s[start++] - 'a']++
+            }
+        }
+        
+        return res
+    }
+}