Merge pull request #1842 from AlgorithmWithGod/Ukj0ng

[20260127] BOJ / G4 / 약수의 합 / 한종욱

Author: ShinHeeEul

Ukj0ng/202601/27 BOJ G4 약수의 합.md

@@ -0,0 +1,43 @@
+```
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    private static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    private static final int MAX = 1000000;
+    private static long[] f, g;
+    private static int N;
+
+    public static void main(String[] args) throws IOException {
+        int T = Integer.parseInt(br.readLine());
+        f = new long[MAX+1];
+        g = new long[MAX+1];
+
+        Arrays.fill(f, 1);
+
+        for (int i = 2; i <= MAX; i++) {
+            for (int j = 1; i*j <= MAX; j++) {
+                f[i*j] += i;
+            }
+        }
+
+        for (int i = 1; i <= MAX; i++) {
+            g[i] = g[i-1]+f[i];
+        }
+
+        while (T-->0) {
+            init();
+            bw.write(g[N] + "\n");
+        }
+
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+
+    private static void init() throws IOException {
+        N = Integer.parseInt(br.readLine());
+    }
+}
+```