1924A

CF1924A.cpp

@@ -0,0 +1,47 @@
+#include<bits/stdc++.h>
+using namespace std;
+typedef long long LL ;
+typedef pair<int,int> pii;
+const int N = 2e5+50 , mod = 1e9+7;
+
+LL n , m , q , k ,ans , tar , cnt ;
+char c;
+bool pos[26];
+string tmp;
+void AC() {
+    cin >> n >> m >> k ; tar = cnt = 0 ; tmp = "";
+    memset(pos , 0 , sizeof (pos));
+    while (k--) {
+        cin >> c ;
+        cnt += ( !pos[c-'a'] && c - 'a' < m ) ;
+        pos[ c-'a'] = 1;
+        if (cnt == m) {
+            cnt = 0 ; tar++; tmp += c;
+            memset(pos , 0 , sizeof (pos));
+        }
+    }
+    if (tar >= n) {
+        cout << "YES\n";
+    } else {
+        while (tar < n - 1) {
+            tmp += 'a' ; tar++;
+        }
+        for (int i = 0 ; ; i++) {
+            if (!pos[i]) {
+                tmp += (char)(i+'a');
+                break;
+            }
+        }
+        cout << "NO\n" << tmp << '\n';
+    }
+}
+
+int main() {
+    ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
+    int T = 1 ;
+    cin >> T ;
+    while (T--) {
+        AC();
+    }
+    return 0;
+}