1146.快照数组.cpp

/*
 * @lc app=leetcode.cn id=1146 lang=cpp
 *
 * [1146] 快照数组
 */
#include <vector>
#include <map>
using namespace std;

// @lc code=start
class SnapshotArray {
public:
    SnapshotArray(int length) {
        snapCnt = 0;
        map<int,int> t;
        t[0] = 0;

        for(int i = 0;i < length; ++i){
            arr.push_back(t);
        }
    }

    void set(int index, int val) {
        arr[index][snapCnt] = val;
    }

    int snap() {
        snapCnt++;
        return snapCnt-1;
    }

    int get(int index, int snap_id) {
       auto it = arr[index].upper_bound(snap_id);
       it--;
       return arr[index][it->first];
    }
private:
    vector<map<int,int>> arr;
    int snapCnt;
};

/**
 * Your SnapshotArray object will be instantiated and called as such:
 * SnapshotArray* obj = new SnapshotArray(length);
 * obj->set(index,val);
 * int param_2 = obj->snap();
 * int param_3 = obj->get(index,snap_id);
 */
// @lc code=end