Revert "use c++20 idioms in doc examples: nullptr over NULL, ll() over (ll) cast"

This reverts commit 77bba36.

Author: Cameron Custer

library/data_structures_[l,r)/rmq.hpp

@@ -5,7 +5,7 @@
 //!     return min(x, y);
 //!   });
 //!   vector<RMQ<int, function<int(int, int)>>>
-//!     rmqs(3, {{}, nullptr});
+//!     rmqs(3, {{}, NULL});
 //!   rmqs[1] = {a, ranges::min};
 //! @endcode
 //! @time O(nlogn + q)

library/data_structures_[l,r]/rmq.hpp

@@ -5,7 +5,7 @@
 //!     return min(x, y);
 //!   });
 //!   vector<RMQ<int, function<int(int, int)>>>
-//!     rmqs(3, {{}, nullptr});
+//!     rmqs(3, {{}, NULL});
 //!   rmqs[1] = {a, ranges::min};
 //! @endcode
 //! @time O(nlogn + q)

library/flow/hungarian.hpp

@@ -1,7 +1,7 @@
 #pragma once
 //! https://e-maxx.ru/algo/assignment_hungary
 //! @code
-//!   vector cost(n+1,vector(m+1,ll(0)));
+//!   vector cost(n+1,vector(m+1,(ll)0));
 //!   auto [min_weight, l_to_r] = hungarian(cost);
 //! @endcode
 //! cost[i][j] = edge weight, 1<=i<=n<=m; 1<=j<=m

library/strings/manacher/longest_palindrome_query.hpp

@@ -5,7 +5,7 @@
 //! substring
 struct longest_pal_query {
   vi man;
-  RMQ<int, function<int(int, int)>> rmq = {{}, nullptr};
+  RMQ<int, function<int(int, int)>> rmq = {{}, NULL};
   //! @param s string/vector
   //! @time O(n log n)
   //! @space O(n log n) for rmq, everything else is O(n)

library/trees/lca_rmq.hpp

@@ -12,7 +12,7 @@
 struct LCA {
   int n;
   vi tin, siz, d, p;
-  RMQ<int, function<int(int, int)>> rmq = {{}, nullptr};
+  RMQ<int, function<int(int, int)>> rmq = {{}, NULL};
   LCA(const auto& g):
     n(sz(g)), tin(n), siz(n, 1), d(n), p(n) {
     vi order;