题解 | #设计LRU缓存结构#

照着题意码吧

class Solution {
public:
    /**
     * lru design
     * @param operators int整型vector<vector<>> the ops
     * @param k int整型 the k
     * @return int整型vector
     */
    int find(queue<pair<int,int>>q,int num)
    {
        int size = q.size();
        for(int i = 0;i < size;i ++)
        {
            auto a = q.front();
            if(a.first == num)
            {
                return a.second;
            }
            q.pop();
        }
        return -1;
    }
    void sort(queue<pair<int,int>> &q,int key)
    {
        queue<pair<int,int>> temp;
        int size = q.size();
        pair<int,int> te;
        for(int i = 0;i < size;i ++)
        {
            auto a = q.front();
            if(a.first == key)
            {
                te = a;
            }
            else
            {
                temp.push(a);
            }
            q.pop();
        }
        temp.push(te);
     //   int i = 0;
        while(temp.size())
        {
            te = temp.front();
            temp.pop();
            q.push(te);
           // cout << i << te.first  << te.second << endl;
           // i ++;
        }
    }
    vector<int> LRU(vector<vector<int> >& operators, int k) {
        // write code here
        vector<int> result;
        queue<pair<int,int>> q;
        int size = operators.size();
        for(int i = 0;i < size;i ++)
        {
            if(operators[i][0] == 1)//set
            {
                if(q.size() == k)
                {
                    q.pop();//出队
                }
                q.push({operators[i][1],operators[i][2]});
            }
            else if(operators[i][0] == 2)//get
            {
                int temp_num = find(q,operators[i][1]);
                result.push_back(temp_num);
                if(temp_num == -1)
                {
                    continue;
                }
            }
            sort(q,operators[i][1]);
        }
        return result;
    }
};