Merge pull request #1442 from AlgorithmWithGod/lkhyun

[20251118] PGM / Lv2 / [3차] 파일명 정렬 / 이강현

Author: ShinHeeEul

lkhyun/202511/18 PGM Lv2 [3차] 파일명 정렬.md

@@ -0,0 +1,44 @@
+```java
+import java.util.stream.*;
+class Solution {
+    static class File implements Comparable<File>{
+        String fileName;
+        String HEAD;
+        int NUMBER;
+        int index;
+        
+        File(String fileName, int index){
+            this.fileName = fileName;
+            
+            int i = 0;
+            while(i<fileName.length() && !Character.isDigit(fileName.charAt(i))) i++;
+            HEAD = fileName.substring(0,i);
+            
+            int j = i;
+            while(j<fileName.length() && Character.isDigit(fileName.charAt(j))) j++;
+            NUMBER = Integer.parseInt(fileName.substring(i,j));
+            
+            this.index = index;
+        }
+        
+        @Override
+        public int compareTo(File o){
+            int compare1 = this.HEAD.toLowerCase().compareTo(o.HEAD.toLowerCase());
+            if(compare1 != 0) return compare1;
+            
+            int compare2 = Integer.compare(this.NUMBER, o.NUMBER);
+            if(compare2 != 0) return compare2;
+            
+            return Integer.compare(this.index, o.index);
+        }
+        
+    }
+    public String[] solution(String[] files) {
+        return IntStream.range(0,files.length)
+                        .mapToObj(i -> new File(files[i],i))
+                        .sorted()
+                        .map(i -> i.fileName)
+                        .toArray(String[]::new);
+    }
+}
+```