Welcome to Subscribe On Youtube
2276. Count Integers in Intervals
Description
Given an empty set of intervals, implement a data structure that can:
- Add an interval to the set of intervals.
- Count the number of integers that are present in at least one interval.
Implement the CountIntervals
class:
CountIntervals()
Initializes the object with an empty set of intervals.void add(int left, int right)
Adds the interval[left, right]
to the set of intervals.int count()
Returns the number of integers that are present in at least one interval.
Note that an interval [left, right]
denotes all the integers x
where left <= x <= right
.
Example 1:
Input ["CountIntervals", "add", "add", "count", "add", "count"] [[], [2, 3], [7, 10], [], [5, 8], []] Output [null, null, null, 6, null, 8] Explanation CountIntervals countIntervals = new CountIntervals(); // initialize the object with an empty set of intervals. countIntervals.add(2, 3); // add [2, 3] to the set of intervals. countIntervals.add(7, 10); // add [7, 10] to the set of intervals. countIntervals.count(); // return 6 // the integers 2 and 3 are present in the interval [2, 3]. // the integers 7, 8, 9, and 10 are present in the interval [7, 10]. countIntervals.add(5, 8); // add [5, 8] to the set of intervals. countIntervals.count(); // return 8 // the integers 2 and 3 are present in the interval [2, 3]. // the integers 5 and 6 are present in the interval [5, 8]. // the integers 7 and 8 are present in the intervals [5, 8] and [7, 10]. // the integers 9 and 10 are present in the interval [7, 10].
Constraints:
1 <= left <= right <= 109
- At most
105
calls in total will be made toadd
andcount
. - At least one call will be made to
count
.
Solutions
-
class Node { Node left; Node right; int l; int r; int mid; int v; int add; public Node(int l, int r) { this.l = l; this.r = r; this.mid = (l + r) >> 1; } } class SegmentTree { private Node root = new Node(1, (int) 1e9 + 1); public SegmentTree() { } public void modify(int l, int r, int v) { modify(l, r, v, root); } public void modify(int l, int r, int v, Node node) { if (l > r) { return; } if (node.l >= l && node.r <= r) { node.v = node.r - node.l + 1; node.add = v; return; } pushdown(node); if (l <= node.mid) { modify(l, r, v, node.left); } if (r > node.mid) { modify(l, r, v, node.right); } pushup(node); } public int query(int l, int r) { return query(l, r, root); } public int query(int l, int r, Node node) { if (l > r) { return 0; } if (node.l >= l && node.r <= r) { return node.v; } pushdown(node); int v = 0; if (l <= node.mid) { v += query(l, r, node.left); } if (r > node.mid) { v += query(l, r, node.right); } return v; } public void pushup(Node node) { node.v = node.left.v + node.right.v; } public void pushdown(Node node) { if (node.left == null) { node.left = new Node(node.l, node.mid); } if (node.right == null) { node.right = new Node(node.mid + 1, node.r); } if (node.add != 0) { Node left = node.left, right = node.right; left.add = node.add; right.add = node.add; left.v = left.r - left.l + 1; right.v = right.r - right.l + 1; node.add = 0; } } } class CountIntervals { private SegmentTree tree = new SegmentTree(); public CountIntervals() { } public void add(int left, int right) { tree.modify(left, right, 1); } public int count() { return tree.query(1, (int) 1e9); } } /** * Your CountIntervals object will be instantiated and called as such: * CountIntervals obj = new CountIntervals(); * obj.add(left,right); * int param_2 = obj.count(); */
-
class Node { public: Node(int l, int r) : l(l) , r(r) , mid((l + r) / 2) , v(0) , add(0) , left(nullptr) , right(nullptr) {} int l, r, mid, v, add; Node* left; Node* right; }; class SegmentTree { public: SegmentTree() : root(new Node(1, 1000000001)) {} void modify(int l, int r, int v, Node* node = nullptr) { if (node == nullptr) { node = root; } if (l > r) { return; } if (node->l >= l && node->r <= r) { node->v = node->r - node->l + 1; node->add = v; return; } pushdown(node); if (l <= node->mid) { modify(l, r, v, node->left); } if (r > node->mid) { modify(l, r, v, node->right); } pushup(node); } int query(int l, int r, Node* node = nullptr) { if (node == nullptr) { node = root; } if (l > r) { return 0; } if (node->l >= l && node->r <= r) { return node->v; } pushdown(node); int v = 0; if (l <= node->mid) { v += query(l, r, node->left); } if (r > node->mid) { v += query(l, r, node->right); } return v; } private: Node* root; void pushup(Node* node) { node->v = node->left->v + node->right->v; } void pushdown(Node* node) { if (node->left == nullptr) { node->left = new Node(node->l, node->mid); } if (node->right == nullptr) { node->right = new Node(node->mid + 1, node->r); } if (node->add != 0) { Node* left = node->left; Node* right = node->right; left->add = node->add; right->add = node->add; left->v = left->r - left->l + 1; right->v = right->r - right->l + 1; node->add = 0; } } }; class CountIntervals { public: CountIntervals() {} void add(int left, int right) { tree.modify(left, right, 1); } int count() { return tree.query(1, 1000000000); } private: SegmentTree tree; }; /** * Your CountIntervals object will be instantiated and called as such: * CountIntervals* obj = new CountIntervals(); * obj->add(left,right); * int param_2 = obj->count(); */
-
class Node: def __init__(self): self.tag = 0 self.tot = 0 self.left = None self.right = None def update(self, l, r, a, b): if self.tag == 1: return mid = (a + b) >> 1 if l == a and r == b: self.tag = 1 self.tot = b - a + 1 return if not self.left: self.left = Node() if not self.right: self.right = Node() if mid >= l: self.left.update(l, min(mid, r), a, mid) if mid + 1 <= r: self.right.update(max(mid + 1, l), r, mid + 1, b) self.tag = 0 self.tot = self.left.tot + self.right.tot class CountIntervals: def __init__(self): self.tree = Node() def add(self, left: int, right: int) -> None: self.tree.update(left, right, 0, 1000000010) def count(self) -> int: return self.tree.tot # Your CountIntervals object will be instantiated and called as such: # obj = CountIntervals() # obj.add(left,right) # param_2 = obj.count()
-
type Node struct { left *Node right *Node l int r int mid int v int add int } type SegmentTree struct { root *Node } func newNode(l, r int) *Node { return &Node{ left: nil, right: nil, l: l, r: r, mid: (l + r) / 2, v: 0, add: 0, } } func newSegmentTree() *SegmentTree { return &SegmentTree{ root: newNode(1, 1000000001), } } func (st *SegmentTree) modify(l, r, v int, node *Node) { if node == nil { node = st.root } if l > r { return } if node.l >= l && node.r <= r { node.v = node.r - node.l + 1 node.add = v return } st.pushdown(node) if l <= node.mid { st.modify(l, r, v, node.left) } if r > node.mid { st.modify(l, r, v, node.right) } st.pushup(node) } func (st *SegmentTree) query(l, r int, node *Node) int { if node == nil { node = st.root } if l > r { return 0 } if node.l >= l && node.r <= r { return node.v } st.pushdown(node) v := 0 if l <= node.mid { v += st.query(l, r, node.left) } if r > node.mid { v += st.query(l, r, node.right) } return v } func (st *SegmentTree) pushup(node *Node) { node.v = node.left.v + node.right.v } func (st *SegmentTree) pushdown(node *Node) { if node.left == nil { node.left = newNode(node.l, node.mid) } if node.right == nil { node.right = newNode(node.mid+1, node.r) } if node.add != 0 { left := node.left right := node.right left.add = node.add right.add = node.add left.v = left.r - left.l + 1 right.v = right.r - right.l + 1 node.add = 0 } } type CountIntervals struct { tree *SegmentTree } func Constructor() CountIntervals { return CountIntervals{ tree: newSegmentTree(), } } func (ci *CountIntervals) Add(left, right int) { ci.tree.modify(left, right, 1, nil) } func (ci *CountIntervals) Count() int { return ci.tree.query(1, 1000000000, nil) } /** * Your CountIntervals object will be instantiated and called as such: * obj := Constructor(); * obj.Add(left,right); * param_2 := obj.Count(); */
-
class CountIntervals { left: null | CountIntervals; right: null | CountIntervals; start: number; end: number; sum: number; constructor(start: number = 0, end: number = 10 ** 9) { this.left = null; this.right = null; this.start = start; this.end = end; this.sum = 0; } add(left: number, right: number): void { if (this.sum == this.end - this.start + 1) return; if (left <= this.start && right >= this.end) { this.sum = this.end - this.start + 1; return; } let mid = (this.start + this.end) >> 1; if (!this.left) this.left = new CountIntervals(this.start, mid); if (!this.right) this.right = new CountIntervals(mid + 1, this.end); if (left <= mid) this.left.add(left, right); if (right > mid) this.right.add(left, right); this.sum = this.left.sum + this.right.sum; } count(): number { return this.sum; } } /** * Your CountIntervals object will be instantiated and called as such: * var obj = new CountIntervals() * obj.add(left,right) * var param_2 = obj.count() */