[20250319] BOJ / 골드1 / K번째 수 / 신동윤

Author: 03do-new30

03do-new30/202503/19 BOJ G1 K번째 수.md

@@ -0,0 +1,28 @@
+```java
+import java.util.*;
+public class Main {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int n = sc.nextInt();
+        int k = sc.nextInt();
+        // 이분탐색
+        long left = 0L;
+        long right = (long) n * n;
+        long answer = 0;
+        while (left <= right) {
+            long mid = (left + right) / 2;
+            long cnt = 0;
+            for (int i = 1; i <= n; i++) {
+                cnt += Math.min(mid / i, n);
+            }
+            if (cnt >= k) {
+                answer = mid;
+                right = mid - 1;
+            } else {
+                left = mid + 1;
+            }
+        }
+        System.out.println(answer);
+    }
+}
+```