부분수열의합_2 (#63)

Author: asqwklop12

pr/부분수열의 합_2/Main.java

@@ -0,0 +1,43 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static int n;
+    static int[] arr;
+    // N=20, max val=100,000 => Max sum = 2,000,000
+    static boolean[] check = new boolean[2000001];
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        n = sc.nextInt();
+        arr = new int[n];
+        for (int i = 0; i < n; i++) {
+            arr[i] = sc.nextInt();
+        }
+
+        solve();
+    }
+
+    public static void solve() {
+        dfs(0, 0);
+
+        // Find the smallest natural number (starting from 1)
+        for (int i = 1; i < check.length; i++) {
+            if (!check[i]) {
+                System.out.println(i);
+                break;
+            }
+        }
+    }
+
+    public static void dfs(int depth, int sum) {
+        if (depth == n) {
+            check[sum] = true;
+            return;
+        }
+
+        dfs(depth + 1, arr[depth] + sum);
+        dfs(depth + 1, sum);
+
+    }
+}