diff --git a/segmenttree/binary_indexed_tree.hpp b/segmenttree/binary_indexed_tree.hpp index 88ace04b..0107b6e1 100644 --- a/segmenttree/binary_indexed_tree.hpp +++ b/segmenttree/binary_indexed_tree.hpp @@ -8,6 +8,17 @@ template struct BIT { int n; std::vector data; BIT(int len = 0) : n(len), data(len) {} + BIT(const T *const a, const int len) : BIT(len) { + T p = 0; + for (int i = 0; i < n; i++) { + data[i] = p += a[i]; + } + for (int j = n - 1; j > 1; j--) { + const int i = j & (j + 1); + if (i > 0) data[j] -= data[i - 1]; + } + } + BIT(const std::vector &v) : BIT(v.data(), int(v.size())) {} void reset() { std::fill(data.begin(), data.end(), T(0)); } void add(int pos, T v) { // a[pos] += v pos++; pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.

Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy