subcrip
/
cp-templates
1
0
Fork 0
Code

Update include.hh 

Signed-off-by: subcrip <contact@subc.rip>
This commit is contained in:
subcrip 2024-04-25 19:11:46 +08:00
parent a053db4b9b
commit 8af9e8d96f
1 changed files with 17 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
include.hh
View File

@ -120,6 +120,23 @@ struct pair_hash {
}
};
uniform_int_distribution<mt19937::result_type> dist(PRIME);
const size_t __array_hash_b = 31, __array_hash_mdl1 = dist(rd), __array_hash_mdl2 = dist(rd);
struct array_hash {
template <typename Sequence>
size_t operator()(const Sequence& arr) const {
size_t pw1 = 1, pw2 = 1;
size_t res1 = 0, res2 = 0;
for (auto&& x : arr) {
res1 = (res1 + x * pw1) % __array_hash_mdl1;
res2 = (res2 + x * pw2) % __array_hash_mdl2;
pw1 = (pw1 * __array_hash_b) % __array_hash_mdl1;
pw2 = (pw2 * __array_hash_b) % __array_hash_mdl2;
}
return res1 + res2;
}
};
/* build data structures */
#define unordered_counter(from, to) __AS_PROCEDURE(unordered_map<__as_typeof(from), size_t, safe_hash> to; for (auto&& x : from) ++to[x];)
#define counter(from, to, cmp) __AS_PROCEDURE(map<__as_typeof(from), size_t, cmp> to; for (auto&& x : from) ++to[x];)