diff --git a/DataStructure/STL/pbds_faster_map.h b/DataStructure/STL/pbds_faster_map.h
index c83c997..116ad34 100644
--- a/DataStructure/STL/pbds_faster_map.h
+++ b/DataStructure/STL/pbds_faster_map.h
@@ -1,5 +1,10 @@
 // From https://codeforces.com/blog/entry/60737
 
+// Note: it's probably useful to test if these tricks make unordered_map fast enough first:
+// unordered_map<...> mp;
+// mp.reserve(N);   // maybe use 2^x?
+// mp.max_load_factor(0.25);
+
 // Code copied from https://codeforces.com/contest/1006/submission/41804666
 #include <ext/pb_ds/assoc_container.hpp>
 using namespace __gnu_pbds;
diff --git a/DataStructure/misc/vec.h b/DataStructure/misc/ndvec.h
similarity index 100%
rename from DataStructure/misc/vec.h
rename to DataStructure/misc/ndvec.h
diff --git a/Math/NumberTheory/Pollard.h b/Math/NumberTheory/Pollard_factorize.h
similarity index 100%
rename from Math/NumberTheory/Pollard.h
rename to Math/NumberTheory/Pollard_factorize.h
diff --git a/Math/NumberTheory/cnt_divisors.h b/Math/NumberTheory/cnt_divisors.h
index e58e33c..8c6235a 100644
--- a/Math/NumberTheory/cnt_divisors.h
+++ b/Math/NumberTheory/cnt_divisors.h
@@ -1,4 +1,4 @@
-#include "Pollard.h"
+#include "Pollard_factorize.h"
 #include "../Prime/Sieve.h"
 
 // Tested: https://www.spoj.com/problems/NUMDIV/
diff --git a/Math/tests/aizu_ntl_1_a_factorize.test.cpp b/Math/tests/aizu_ntl_1_a_factorize.test.cpp
index dc3f4f9..26d355d 100644
--- a/Math/tests/aizu_ntl_1_a_factorize.test.cpp
+++ b/Math/tests/aizu_ntl_1_a_factorize.test.cpp
@@ -1,7 +1,7 @@
 #define PROBLEM "https://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=NTL_1_A"
 
 #include "../../template.h"
-#include "../NumberTheory/Pollard.h"
+#include "../NumberTheory/Pollard_factorize.h"
 
 void solve() {
     int n;
diff --git a/Math/tests/factorize.test.cpp b/Math/tests/factorize.test.cpp
index 12bdf28..0c7aca5 100644
--- a/Math/tests/factorize.test.cpp
+++ b/Math/tests/factorize.test.cpp
@@ -9,7 +9,7 @@ long long get_rand(long long r) {
     return uniform_int_distribution<long long> (0, r-1)(rng);
 }
 
-#include "../NumberTheory/Pollard.h"
+#include "../NumberTheory/Pollard_factorize.h"
 
 int32_t main() {
     ios::sync_with_stdio(0); cin.tie(0);
diff --git a/Math/tests/is_prime_yukicoder.test.cpp b/Math/tests/is_prime_yukicoder.test.cpp
index 86ceb38..62e773c 100644
--- a/Math/tests/is_prime_yukicoder.test.cpp
+++ b/Math/tests/is_prime_yukicoder.test.cpp
@@ -1,7 +1,7 @@
 #define PROBLEM "https://yukicoder.me/problems/no/3030"
 
 #include "../../template.h"
-#include "../NumberTheory/Pollard.h"
+#include "../NumberTheory/Pollard_factorize.h"
 
 void solve() {
     int q; cin >> q;