ATCODER, started on beginner contest 249

atcoder/beginner_contests/249/b.cpp

@@ -0,0 +1,40 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+
+int main(){
+    ios::sync_with_stdio(0);
+    cin.tie(0);
+
+    string s;
+    cin >> s;
+
+    set<char> seen;
+    bool lower = false, upper = false;
+
+    for(char c : s){
+        if(isupper(c)){
+            upper = true;
+        }
+        else if(islower(c)){
+            lower = true;
+        }
+
+        if(seen.count(c)){
+            cout << "No" << endl;
+            return 0;
+        }
+        seen.insert(c);
+    }
+
+    if(lower && upper){
+        cout << "Yes" << endl;
+    } else{
+        cout << "No" << endl;
+    }
+
+    cout << flush;
+
+    return 0;
+}