[week9](gmlwls96) Minimum Window Substring

Author: gmlwls96

minimum-window-substring/gmlwls96.kt

@@ -0,0 +1,32 @@
+class Solution {
+    fun minWindow(s: String, t: String): String {
+        if (s.length < t.length) {
+            return ""
+        }
+        val containIndexList = mutableListOf<Int>()
+        for (i in s.indices) {
+            if (t.contains(s[i])) {
+                containIndexList.add(i)
+            }
+        }
+        var answer = ""
+        val regex =
+            t.toCharArray().joinToString(separator = "", prefix = "^", postfix = ".+$") { """(?=.*${it})""" }.toRegex()
+        for (i in 0..containIndexList.size - t.length) {
+            val startIndex = containIndexList[i]
+            for (l in t.length..containIndexList.size - i) {
+                val endIndex = containIndexList[(i + l) - 1] + 1
+                val subStr = s.substring(startIndex, endIndex)
+                if (regex.containsMatchIn(subStr)) {
+                    if (answer.isEmpty()) {
+                        answer = subStr
+                    } else if (subStr.length < answer.length) {
+                        answer = subStr
+                    }
+                    break
+                }
+            }
+        }
+        return answer
+    }
+}