feat(codeforces/937): a-f

codeforces/937/e.cc

@@ -0,0 +1,70 @@
+#include <bits/stdc++.h>  // {{{
+
+// https://codeforces.com/blog/entry/96344
+
+#pragma GCC optimize("O2,unroll-loops")
+#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
+
+using namespace std;
+
+using i32 = int32_t;
+using u32 = uint32_t;
+using i64 = int64_t;
+using u64 = uint64_t;
+using f64 = double;
+using f128 = long double;
+//  }}}
+
+void solve() {
+  u32 n;
+  cin >> n;
+  string s;
+  cin >> s;
+  u64 ans = n;
+  for (u32 i = 1; i < n; ++i) {
+    if (n % i) {
+      continue;
+    }
+    unordered_map<string, int> seen;
+    bool bad = false;
+    for (u32 j = 0; j < n; j += i) {
+      ++seen[s.substr(j, i)];
+      if (seen.size() > 2) {
+        bad = true;
+        break;
+      }
+    }
+    if (bad)
+      continue;
+    if (seen.size() == 1) {
+      ans = i;
+      break;
+    } else if (seen.size() == 2) {
+      int first = seen.begin()->second, second = next(seen.begin())->second;
+      int diff = 0;
+      for (u32 j = 0; j < seen.begin()->first.size(); ++j) {
+        diff += seen.begin()->first[j] != next(seen.begin())->first[j];
+      }
+      if ((first == 1 || second == 1) && diff <= 1) {
+        ans = i;
+        break;
+      }
+    }
+  }
+  cout << ans << endl;
+}
+
+int main() {  // {{{
+  cin.tie(nullptr)->sync_with_stdio(false);
+  cin.exceptions(cin.failbit);
+
+  int tc = 1;
+  cin >> tc;
+
+  for (int t = 0; t < tc; ++t) {
+    solve();
+  }
+
+  return 0;
+}
+// }}}