64 lines
1.2 KiB
C++
64 lines
1.2 KiB
C++
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#include <algorithm>
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#include <cassert>
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#include <map>
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#include <vector>
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class SnapshotArray {
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int snap_id = 0;
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std::vector<std::map<int, int>> arr;
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public:
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SnapshotArray(int length)
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: arr(length, std::map<int, int> { { 0, 0 } })
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{
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}
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void set(int index, int val)
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{
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arr[index][snap_id] = val;
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}
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int snap()
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{
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return snap_id++;
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}
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int get(int index, int snap_id)
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{
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auto it = std::prev(arr[index].lower_bound(snap_id + 1));
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return it == arr[index].end() ? 0 : it->second;
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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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int main()
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{
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SnapshotArray arr(3);
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arr.set(0, 5);
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assert(arr.snap() == 0);
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arr.set(0, 6);
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assert(arr.get(0, 0) == 5);
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assert(arr.get(0, 1) == 6);
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arr = SnapshotArray(1);
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arr.set(0, 15);
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assert(arr.snap() == 0);
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assert(arr.snap() == 1);
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assert(arr.snap() == 2);
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assert(arr.get(0, 2) == 15);
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assert(arr.snap() == 3);
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assert(arr.snap() == 4);
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assert(arr.get(0, 0) == 15);
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return 0;
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}
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