subcrip
/
cp-templates
1
0
Fork 0
Code

Create segtree.cc

This commit is contained in:
Ariel 2024-02-01 23:07:20 +08:00 committed by GitHub
parent 31eadd2f23
commit c2a5a06187
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
1 changed files with 47 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

47
trees/segtree.cc Normal file
View File

@ -0,0 +1,47 @@
template<typename T> class segtree {
private:
using size_type = __uint64_t;
T _max;
vector<T> d, b;
void _update(size_type s, size_type t, size_type p, size_type l, size_type r, T c) {
if (l <= s && t <= r) {
d[p] += c * (t - s + 1);
b[p] += c;
return;
}
size_type m = s + (t - s >> 1);
if (b[p] && s != t) {
d[p * 2] += b[p] * (m - s + 1), d[p * 2 + 1] += b[p] * (t - m);
b[p * 2] += b[p], b[p * 2 + 1] += b[p];
b[p] = 0;
}
if (l <= m) _update(s, m, p * 2, l, r, c);
if (r > m) _update(m + 1, t, p * 2 + 1, l, r, c);
d[p] = d[p * 2] + d[p * 2 + 1];
}
T _query(size_type s, size_type t, size_type p, size_type l, size_type r) {
if (l <= s && t <= r) return d[p];
size_type m = s + (t - s >> 1);
T res = {};
if (b[p]) {
d[p * 2] += b[p] * (m - s + 1), d[p * 2 + 1] += b[p] * (t - m);
b[p * 2] += b[p], b[p * 2 + 1] += b[p];
b[p] = 0;
}
if (l <= m) res += _query(s, m, p * 2, l, r);
if (r > m) res += _query(m + 1, t, p * 2 + 1, l, r);
return res;
}
public:
segtree(T _max) : d(4 * _max, {}), b(4 * _max, {}), _max(_max) {}
void update(size_type l, size_type r, T c) {
_update({}, _max, 1, l, r, c);
}
T query(size_type l, size_type r) {
return _query({}, _max, 1, l, r);
}
};