/
longest-substring-of-one-repeating-character.cpp
198 lines (183 loc) · 6.14 KB
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longest-substring-of-one-repeating-character.cpp
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// Time: O(nlogn)
// Space: O(n)
template <typename Node, typename T>
class SegmentTree {
public:
explicit SegmentTree(
int N,
const function<Node(const int&)>& build_fn,
const function<Node(const T&)>& update_fn,
const function<Node(const Node&, const Node&)>& query_fn)
: tree(N > 1 ? 1 << (__lg(N - 1) + 2) : 2),
base_(N > 1 ? 1 << (__lg(N - 1) + 1) : 1),
build_fn_(build_fn),
query_fn_(query_fn),
update_fn_(update_fn) {
for (int i = base_; i < base_ + N; ++i) {
tree[i] = build_fn_(i - base_);
}
for (int i = base_ - 1; i >= 1; --i) {
tree[i] = query_fn_(tree[2 * i], tree[2 * i + 1]);
}
}
void update(int i, const T& h) {
int x = base_ + i;
tree[x] = update_fn_(h);
while (x > 1) {
x /= 2;
tree[x] = query_fn_(tree[x * 2], tree[x * 2 + 1]);
}
}
vector<Node> tree;
private:
int base_;
const function<Node(const int&)> build_fn_;
const function<Node(const T&)> update_fn_;
const function<Node(const Node&, const Node&)> query_fn_;
};
// segment tree
class Solution {
public:
vector<int> longestRepeating(string s, string queryCharacters, vector<int>& queryIndices) {
struct Node {
Node(char left = 0, char right = 0, int left_len = 0, int right_len = 0, int len = 0, int max_len = 0)
: left(left), right(right), left_len(left_len), right_len(right_len), len(len), max_len(max_len) {
}
char left;
char right;
int left_len;
int right_len;
int len;
int max_len;
};
const auto& update = [] (const auto& c) {
return Node(c, c, 1, 1, 1, 1);
};
const auto& build = [&s, &update] (const auto& i) {
return update(s[i]);
};
const auto& query = [] (const auto& x, const auto& y) {
if (x.len == 0) {
return y;
}
if (y.len == 0) {
return x;
}
return Node(x.left,
y.right,
x.left_len + ((x.left_len == x.len && x.right == y.left) ? y.left_len : 0),
y.right_len + ((y.right_len == y.len && y.left == x.right) ? x.right_len : 0),
x.len + y.len,
max({x.max_len, y.max_len, (x.right == y.left) ? x.right_len + y.left_len : 0}));
};
vector<int> result;
SegmentTree<Node, char> st(size(s), build, update, query);
for (int i = 0; i < size(queryCharacters); ++i) {
st.update(queryIndices[i], queryCharacters[i]);
result.emplace_back(st.tree[1].max_len);
}
return result;
}
};
// Time: O(nlogn)
// Space: O(n)
template <typename Node, typename T>
class SegmentTree2 {
public:
explicit SegmentTree2(
int N,
const function<Node(const int&)>& build_fn,
const function<Node(const T&)>& update_fn,
const function<Node(const Node&, const Node&)>& query_fn)
: tree_(N > 1 ? 1 << (__lg(N - 1) + 2) : 2),
base_(N > 1 ? 1 << (__lg(N - 1) + 1) : 1),
build_fn_(build_fn),
query_fn_(query_fn),
update_fn_(update_fn) {
for (int i = base_; i < base_ + N; ++i) {
tree_[i] = build_fn_(i - base_);
}
for (int i = base_ - 1; i >= 1; --i) {
tree_[i] = query_fn_(tree_[2 * i], tree_[2 * i + 1]);
}
}
void update(int i, const T& h) {
int x = base_ + i;
tree_[x] = update_fn_(h);
while (x > 1) {
x /= 2;
tree_[x] = query_fn_(tree_[x * 2], tree_[x * 2 + 1]);
}
}
Node query(int L, int R) {
Node none;
if (L > R) {
return none;
}
L += base_;
R += base_;
auto left = none;
auto right = none;
for (; L <= R; L /= 2, R /= 2) {
if (L & 1) {
left = query_fn_(left, tree_[L]);
++L;
}
if ((R & 1) == 0) {
right = query_fn_(tree_[R], right);
--R;
}
}
return query_fn_(left, right);
}
private:
vector<Node> tree_;
int base_;
const function<Node(const int&)> build_fn_;
const function<Node(const T&)> update_fn_;
const function<Node(const Node&, const Node&)> query_fn_;
};
// segment tree
class Solution2 {
public:
vector<int> longestRepeating(string s, string queryCharacters, vector<int>& queryIndices) {
struct Node {
Node(char left = 0, char right = 0, int left_len = 0, int right_len = 0, int len = 0, int max_len = 0)
: left(left), right(right), left_len(left_len), right_len(right_len), len(len), max_len(max_len) {
}
char left;
char right;
int left_len;
int right_len;
int len;
int max_len;
};
const auto& update = [] (const auto& c) {
return Node(c, c, 1, 1, 1, 1);
};
const auto& build = [&s, &update] (const auto& i) {
return update(s[i]);
};
const auto& query = [] (const auto& x, const auto& y) {
if (x.len == 0) {
return y;
}
if (y.len == 0) {
return x;
}
return Node(x.left,
y.right,
x.left_len + ((x.left_len == x.len && x.right == y.left) ? y.left_len : 0),
y.right_len + ((y.right_len == y.len && y.left == x.right) ? x.right_len : 0),
x.len + y.len,
max({x.max_len, y.max_len, (x.right == y.left) ? x.right_len + y.left_len : 0}));
};
vector<int> result;
SegmentTree2<Node, char> st(size(s), build, update, query);
for (int i = 0; i < size(queryCharacters); ++i) {
st.update(queryIndices[i], queryCharacters[i]);
result.emplace_back(st.query(0, size(s) - 1).max_len);
}
return result;
}
};