题解 | 机器翻译

#include <iostream>
#include <queue>
#include <unordered_set>
using namespace std;

int main() {
    int n, size, code;
    cin >> n >> size;
    queue<int> cacheQueue;
    unordered_set<int> cacheSet;
    int misses = 0;

    while (size--) {
        cin >> code;
        if (cacheSet.find(code) == cacheSet.end()) {
            misses++;
            if (cacheQueue.size() >= n) {
                cacheSet.erase(cacheQueue.front());
                cacheQueue.pop();
            }
            cacheQueue.push(code);
            cacheSet.insert(code);
        }
    }

    cout << misses << endl;
    return 0;
}