I tried binary search, harsh table, got TLE. then I thought using direct mapping table could get MLE, but never TLE, so i tried it, still TLE!!!tell me how could this code get TLE.
#include <iostream>
using namespace std;
char a[1000000001];
int main()
{
    int n;
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        int j;
        cin >> j;
        a[j] = 1;
    }
    int m;
    cin >> m;
    int cnt= 0;
    for (int i = 1; i <= m; ++i) {
        int j;
        cin >> j;
        cnt += a[j];
    }
    cout << cnt;
}