update docs

Author: lrvideckis

library/data_structures/seg_tree_uncommon/wavelet_matrix.hpp

@@ -1,11 +1,16 @@
 #pragma once
+//! @code
+//!   vector<ull> a(n);
+//!   wavelet_matrix wm(a, 1e9 /*a[i] <= 1e9*/);
+//!   wm.kth(l, r, k); //(k+1)th smallest number in [l,r)
+//!   wm.kth(l, r, 0); //min in [l,r)
+//! @endcode
+//! @time O(n * log(max_val) + q * log(max_val))
+//! @space O(n * log(max_val) / 64)
 #include "wavelet_bit_vec.hpp"
 struct wavelet_matrix {
   int n;
   vector<bit_vec> bv;
-  //! Requires a[i] <= max_val
-  //! @time O(n * log(max_val))
-  //! @space O(n * log(max_val) / 64)
   wavelet_matrix(vector<ull> a, ull max_val):
     n(sz(a)), bv(bit_width(max_val), {{}}) {
     for (int h = sz(bv); h--;) {
@@ -16,10 +21,6 @@ struct wavelet_matrix {
       bv[h] = b;
     }
   }
-  //! (k+1)th smallest number in [l,r)
-  //! kth(l,r,0) returns the min
-  //! @time O(log(max_val))
-  //! @space O(1)
   ull kth(int l, int r, int k) {
     ll res = 0;
     for (int h = sz(bv); h--;) {