issue #27 big Sorting java w/ Explanation

sowon-dev · sowon-dev · commit 0bb337436b4e · 2021-03-14T11:54:24.000+09:00
diff --git a/src/hackerrank/BigSorting.java b/src/hackerrank/BigSorting.java
@@ -1,23 +1,71 @@
 package hackerrank;
 
 import java.util.Arrays;
+import java.util.Scanner;
 
 public class BigSorting {
+
   static String[] bigSorting(String[] unsorted) {
+    //String 타입의 정렬안된 배열을 숫자오름차순으로 숫자를 정렬하는 문제.
+
+    //첫시도 -실패-> Exception in thread "main" java.lang.NumberFormatException: For input string: "31415926535897932384626433832795"
+    /*
+    //String arr를 long arr로 바꾼다.
     long[] arr = new long[unsorted.length];
 
-    for(int i = 0; i<unsorted.length; i++){
+    for (int i = 0; i < unsorted.length; i++) {
       arr[i] = Long.parseLong(unsorted[i]);
     }
+
+    //long 배열을 오름차순정렬한다.
     Arrays.sort(arr);
 
-    for(int i=0; i<arr.length; i++){
-      unsorted[i] = Object.toString(arr[i]);
+    //정렬한 long배열을 String 배열로 바꾼 뒤 리턴한다.
+    String[] result = new String[unsorted.length];
+    for (int i = 0; i < unsorted.length; i++) {
+      result[i] = Long.toString(arr[i]);
     }
+    System.out.println(Arrays.toString(result));
+    return result;
+    */
+
+    //sol4 람다식 + sort
+//    System.out.println(Arrays.toString(unsorted));
+    Arrays.sort(unsorted, (x, y) -> {
+//      System.out.print("시작 arr: "+Arrays.toString(unsorted) + "   x: "+x+"   y:"+y);
+      if (x.length() == y.length()) {
+//        System.out.print("    x.compareTo(y): "+x.compareTo(y)+"\n");
+        return x.compareTo(y); //자리수에 상관없이 첫째자리만 보고 오름차순 정렬
+      }else {
+//        System.out.print("     x.length() - y.length(): "+ (x.length() - y.length()) +"\n");
+        return x.length() - y.length(); //자리수에 상관한 오름차순 정렬
+      }
+    });
+
     return unsorted;
   }
 
   public static void main(String[] args) {
-    System.out.println(bigSorting(new String[]{"1", "200", "150", "3"}) + ", ans: [1 3 150 200]");
+    Scanner sc = new Scanner(System.in);
+    int n = sc.nextInt();
+    String[] arr = new String[n];
+    for (int i = 0; i < n; i++) {
+      arr[i] = sc.next();
+
+    }
+    arr = bigSorting(arr);
+    for (int i = 0; i < arr.length; i++) {
+      System.out.println(arr[i]);
+    }
+    sc.close();
+/* sample input
+6
+31415926535897932384626433832795
+1
+3
+10
+3
+5
+*/
   }
 }
