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feat: add solutions to lc problem: No.1146
No.1146.Snapshot Array
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‎solution/1100-1199/1146.Snapshot Array/README.md

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Original file line numberDiff line numberDiff line change
@@ -45,22 +45,180 @@ snapshotArr.get(0,0); // 获取 snap_id = 0 的快照中 array[0] 的值，返
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<!-- 这里可写通用的实现逻辑 -->
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**方法一：数组 + 二分查找**
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维护一个数组，数组中的每个元素是一个列表，列表中存储的是每次设置的值以及对应的快照编号。
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每次设置值时，将值和快照编号添加到对应索引的列表中。
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每次获取值时，使用二分查找，找到对应位置第一个大于快照编号 `snap_id` 的值，然后返回前一个值即可。
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时间复杂度上，设置值的时间复杂度为 $O(1)$，快照的时间复杂度为 $O(1)$，获取值的时间复杂度为 $O(\log n)$。
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<!-- tabs:start -->
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### **Python3**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```python
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class SnapshotArray:
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def __init__(self, length: int):
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self.idx = 0
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self.arr = defaultdict(list)
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def set(self, index: int, val: int) -> None:
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self.arr[index].append((self.idx, val))
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def snap(self) -> int:
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self.idx += 1
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return self.idx - 1
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def get(self, index: int, snap_id: int) -> int:
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vals = self.arr[index]
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i = bisect_right(vals, (snap_id, inf)) - 1
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return 0 if i < 0 else vals[i][1]
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# Your SnapshotArray object will be instantiated and called as such:
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# obj = SnapshotArray(length)
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# obj.set(index,val)
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# param_2 = obj.snap()
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# param_3 = obj.get(index,snap_id)
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```
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### **Java**
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<!-- 这里可写当前语言的特殊实现逻辑 -->
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```java
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class SnapshotArray {
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private List<int[]>[] arr;
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private int idx;
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public SnapshotArray(int length) {
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arr = new List[length];
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Arrays.setAll(arr, k -> new ArrayList<>());
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}
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public void set(int index, int val) {
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arr[index].add(new int[] {idx, val});
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}
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public int snap() {
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return idx++;
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}
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public int get(int index, int snap_id) {
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var vals = arr[index];
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int left = 0, right = vals.size();
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while (left < right) {
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int mid = (left + right) >> 1;
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if (vals.get(mid)[0] > snap_id) {
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right = mid;
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} else {
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left = mid + 1;
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}
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}
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return left == 0 ? 0 : vals.get(left - 1)[1];
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}
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}
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/**
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* Your SnapshotArray object will be instantiated and called as such:
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* SnapshotArray obj = new SnapshotArray(length);
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* obj.set(index,val);
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* int param_2 = obj.snap();
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* int param_3 = obj.get(index,snap_id);
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*/
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```
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### **C++**
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```cpp
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class SnapshotArray {
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public:
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SnapshotArray(int length) {
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idx = 0;
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arr = vector<vector<pair<int, int>>>(length);
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}
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void set(int index, int val) {
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arr[index].push_back({idx, val});
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}
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int snap() {
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return idx++;
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}
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int get(int index, int snap_id) {
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auto& vals = arr[index];
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int left = 0, right = vals.size();
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while (left < right) {
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int mid = (left + right) >> 1;
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if (vals[mid].first > snap_id) {
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right = mid;
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} else {
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left = mid + 1;
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}
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}
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return left == 0 ? 0 : vals[left - 1].second;
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}
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private:
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vector<vector<pair<int, int>>> arr;
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int idx;
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};
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/**
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* Your SnapshotArray object will be instantiated and called as such:
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* SnapshotArray* obj = new SnapshotArray(length);
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* obj->set(index,val);
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* int param_2 = obj->snap();
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* int param_3 = obj->get(index,snap_id);
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*/
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```
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### **Go**
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```go
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type SnapshotArray struct {
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idx int
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arr [][]pair
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}
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func Constructor(length int) SnapshotArray {
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return SnapshotArray{0, make([][]pair, length)}
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}
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func (this *SnapshotArray) Set(index int, val int) {
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this.arr[index] = append(this.arr[index], pair{this.idx, val})
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}
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func (this *SnapshotArray) Snap() int {
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this.idx++
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return this.idx - 1
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}
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func (this *SnapshotArray) Get(index int, snap_id int) int {
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vals := this.arr[index]
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i := sort.Search(len(vals), func(i int) bool { return vals[i].i > snap_id })
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if i == 0 {
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return 0
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}
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return vals[i-1].v
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}
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type pair struct{ i, v int }
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/**
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* Your SnapshotArray object will be instantiated and called as such:
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* obj := Constructor(length);
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* obj.Set(index,val);
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* param_2 := obj.Snap();
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* param_3 := obj.Get(index,snap_id);
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*/
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```
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### **...**

‎solution/1100-1199/1146.Snapshot Array/README_EN.md

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Original file line numberDiff line numberDiff line change
@@ -45,13 +45,161 @@ snapshotArr.get(0,0); // Get the value of array[0] with snap_id = 0, return 5</
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### **Python3**
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```python
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class SnapshotArray:
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def __init__(self, length: int):
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self.idx = 0
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self.arr = defaultdict(list)
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def set(self, index: int, val: int) -> None:
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self.arr[index].append((self.idx, val))
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def snap(self) -> int:
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self.idx += 1
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return self.idx - 1
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def get(self, index: int, snap_id: int) -> int:
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vals = self.arr[index]
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i = bisect_right(vals, (snap_id, inf)) - 1
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return 0 if i < 0 else vals[i][1]
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# Your SnapshotArray object will be instantiated and called as such:
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# obj = SnapshotArray(length)
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# obj.set(index,val)
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# param_2 = obj.snap()
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# param_3 = obj.get(index,snap_id)
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```
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### **Java**
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```java
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class SnapshotArray {
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private List<int[]>[] arr;
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private int idx;
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public SnapshotArray(int length) {
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arr = new List[length];
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Arrays.setAll(arr, k -> new ArrayList<>());
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}
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public void set(int index, int val) {
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arr[index].add(new int[] {idx, val});
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}
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public int snap() {
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return idx++;
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}
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public int get(int index, int snap_id) {
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var vals = arr[index];
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int left = 0, right = vals.size();
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while (left < right) {
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int mid = (left + right) >> 1;
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if (vals.get(mid)[0] > snap_id) {
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right = mid;
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} else {
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left = mid + 1;
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}
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}
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return left == 0 ? 0 : vals.get(left - 1)[1];
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}
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}
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/**
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* Your SnapshotArray object will be instantiated and called as such:
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* SnapshotArray obj = new SnapshotArray(length);
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* obj.set(index,val);
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* int param_2 = obj.snap();
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* int param_3 = obj.get(index,snap_id);
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*/
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```
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### **C++**
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```cpp
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class SnapshotArray {
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public:
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SnapshotArray(int length) {
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idx = 0;
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arr = vector<vector<pair<int, int>>>(length);
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}
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void set(int index, int val) {
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arr[index].push_back({idx, val});
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}
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int snap() {
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return idx++;
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}
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int get(int index, int snap_id) {
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auto& vals = arr[index];
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int left = 0, right = vals.size();
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while (left < right) {
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int mid = (left + right) >> 1;
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if (vals[mid].first > snap_id) {
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right = mid;
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} else {
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left = mid + 1;
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}
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}
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return left == 0 ? 0 : vals[left - 1].second;
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}
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private:
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vector<vector<pair<int, int>>> arr;
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int idx;
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};
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/**
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* Your SnapshotArray object will be instantiated and called as such:
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* SnapshotArray* obj = new SnapshotArray(length);
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* obj->set(index,val);
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* int param_2 = obj->snap();
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* int param_3 = obj->get(index,snap_id);
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*/
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```
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### **Go**
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```go
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type SnapshotArray struct {
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idx int
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arr [][]pair
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}
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func Constructor(length int) SnapshotArray {
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return SnapshotArray{0, make([][]pair, length)}
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}
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func (this *SnapshotArray) Set(index int, val int) {
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this.arr[index] = append(this.arr[index], pair{this.idx, val})
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}
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func (this *SnapshotArray) Snap() int {
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this.idx++
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return this.idx - 1
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}
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func (this *SnapshotArray) Get(index int, snap_id int) int {
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vals := this.arr[index]
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i := sort.Search(len(vals), func(i int) bool { return vals[i].i > snap_id })
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if i == 0 {
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return 0
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}
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return vals[i-1].v
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}
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type pair struct{ i, v int }
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/**
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* Your SnapshotArray object will be instantiated and called as such:
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* obj := Constructor(length);
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* obj.Set(index,val);
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* param_2 := obj.Snap();
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* param_3 := obj.Get(index,snap_id);
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*/
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```
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### **...**

‎solution/1100-1199/1146.Snapshot Array/Solution.cpp

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class SnapshotArray {
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public:
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SnapshotArray(int length) {
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idx = 0;
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arr = vector<vector<pair<int, int>>>(length);
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}
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void set(int index, int val) {
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arr[index].push_back({idx, val});
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}
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int snap() {
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return idx++;
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}
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int get(int index, int snap_id) {
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auto& vals = arr[index];
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int left = 0, right = vals.size();
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while (left < right) {
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int mid = (left + right) >> 1;
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if (vals[mid].first > snap_id) {
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right = mid;
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} else {
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left = mid + 1;
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}
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}
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return left == 0 ? 0 : vals[left - 1].second;
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}
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private:
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vector<vector<pair<int, int>>> arr;
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int idx;
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};
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/**
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* Your SnapshotArray object will be instantiated and called as such:
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* SnapshotArray* obj = new SnapshotArray(length);
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* obj->set(index,val);
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* int param_2 = obj->snap();
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* int param_3 = obj->get(index,snap_id);
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*/

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