dotfiles/lua/snippets/bit.lua

24 lines
400 B
Lua

return [[
template<typename T>
struct BIT {
int n;
vector<T> c;
BIT(size_t n) : n(n), c(n + 1) {}
void add(size_t i, const T& k) {
while (i <= n) {
c[i] += k;
i += lowbit(i);
}
}
T getsum(size_t i) {
T res = {};
while (i) {
res += c[i];
i -= lowbit(i);
}
return res;
}
};
]]