[ADD] baekjoon 2438 cpp solution

solutions/baekjoon/2438/main.cpp

@@ -0,0 +1,25 @@
+// Authored by: tony9402
+// Co-authored by: -
+// Link: http://boj.kr/9a6e490b384645388ae1aaefc4c04e8f
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(0);
+
+    int N; cin >> N;
+    for(int i = 1; i <= N; ++i) {
+        for(int j = 1; j <= i; ++j) {
+            cout << "*";
+        }
+        cout << "\n";
+    }
+
+    return 0;
+}
+
+/* Solution Description
+i는 1부터 N까지 j는 1부터 i까지 중첩 반복문으로 풀면 되는 문제.
+*/