[20251108] BOJ / G5 / Hello World! / 이강현

Author: lkhyun

lkhyun/202511/08 BOJ G5 Hello World!.md

@@ -0,0 +1,54 @@
+```java
+import java.util.*;
+import java.io.*;
+
+public class Main{
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    static StringBuilder sb = new StringBuilder();
+    static StringTokenizer st;
+    static int N;
+    static int[] helowrd = new int[7];
+    static boolean[] numbers = new boolean[10];
+    static boolean finished;
+    static int A,B;
+    public static void main(String[] args) throws Exception {
+        N = Integer.parseInt(br.readLine());
+        backtracking(0);
+        if(A == 0){
+            bw.write("No Answer");
+            bw.close();
+            return;
+        }
+        bw.write(String.format("%7d\n", A));
+        bw.write(String.format("+ %5d\n", B));
+        bw.write("-------\n");
+        bw.write(String.format("%7d", N));
+        bw.close();
+    }
+    public static void backtracking(int depth){
+        if(finished) return;
+        if(depth == 7){
+            int a = 10000*helowrd[0] + 1000*helowrd[1] + 100*helowrd[2] + 10*helowrd[2] + helowrd[3];
+            int b = 10000*helowrd[4] + 1000*helowrd[3] + 100*helowrd[5] + 10*helowrd[2] + helowrd[6];
+            if((a+b) == N){
+                finished = true;
+                A = a;
+                B = b;
+            }
+            return;
+        }
+
+        for(int i = 0; i<10; i++){
+            if(depth==0 && i==0) continue;
+            if(depth==4 && i==0) continue;
+            if(!numbers[i]){
+                helowrd[depth] = i;
+                numbers[i] = true;
+                backtracking(depth+1);
+                numbers[i] = false;
+            }
+        }
+    }
+}
+```