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// Ai + Aj > Bi + Bj
// Ai - Bi > Bj - Aj
// -(Bi - Ai) > (Bj - Aj)
// number of elements ci s.t. i < j & ci < -X
// => lower_bound of -x in c[0, j)
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define endl "\n"
const double PI = 3.14159265358979;
const ll INF = 1e9 + 7;
const ll MOD = 1e9 + 7;
const ll nax = 2505;
const int LOG = 25;
void solve() {
int n;
cin >> n;
int a[n], b[n], c[n];
for (int i = 0; i < n; i++) {
cin >> a[i];
}
for (int i = 0; i < n; i++) {
cin >> b[i];
c[i] = b[i] - a[i];
}
sort(c, c + n);
ll cnt = 0;
for (int j = 1; j < n; j++) {
cnt += lower_bound(c, c + j, -c[j]) - c;
}
cout << cnt << endl;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int t; cin >> t; while(t--)
solve();
return 0;
}Editor is loading...
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