두 배열의 합

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
 
typedef long long ll;
 
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
 
    ll t;
    int n, m;
    cin >> t >> n;
 
    vector<int> a, b;
 
    for (int i = 0; i < n; i++) {
        int tmp;
        cin >> tmp;
        a.push_back(tmp);
    }
 
    cin >> m;
 
    for (int i = 0; i < m; i++) {
        int tmp;
        cin >> tmp;
        b.push_back(tmp);
    }
 
    vector<ll> resA, resB;
 
    //모든 부분합을 구한다.
    for (int i = 0; i < n; i++) {
        ll tmp = a[i];
        resA.push_back(tmp);
        for (int j = i+1; j < n; j++) {
            tmp += a[j];
            resA.push_back(tmp);
        }
    }
 
    
    for (int i = 0; i < m; i++) {
        ll tmp = b[i];
        resB.push_back(tmp);
        for (int j = i+1; j < m; j++) {
            tmp += b[j];
            resB.push_back(tmp);
        }
    }
 
    sort(resB.begin(), resB.end());
    // cout << "debug A ";
    // for (int i = 0; i < resA.size(); i++) cout << resA[i] << ' ';
    // cout << '\n';
    // cout << "debug B ";
    // for (int i = 0; i < resB.size(); i++) cout << resB[i] << ' ';
 
    ll ans = 0;
    for (int i = 0; i < resA.size(); i++) {
        ll diff = t - resA[i]; //이 차이만큼을 B가 채우면 ok 
 
        vector<ll> ::iterator up = upper_bound(resB.begin(), resB.end(), diff);
        vector<ll> ::iterator lo = lower_bound(resB.begin(), resB.end(), diff);
        ans += up-lo;     
    }
    cout << ans << '\n';
 
    return 0;
}