就是考数据结构的使用 int main(){ int n; map<int, set<int>> record; cin >> n; int tem; for (int i = 0; i < n; i++) { cin >> tem; record[tem].insert(i+1); } int q; cin >> q; vector<int>result(q); int l, r, k; int num = 0; for (int i = 0; i < q; i++) { cin >> l >> r >> k; num = 0; for (set<int>::iterator s = record[k].begin();s != record[k].end(); s++) { if ((*s) >= l && (*s) <= r){ num++; } } result[i] = num; } for (int i = 0; i < q; i++) { cout << result[i] << endl; } return 0; }