[Link] https://www.acmicpc.net/problem/7578
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#include <algorithm>
#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
// #include <bits/stdc++.h>
using namespace std;
#define for0(i, n) for(int i = 0; i < n; i++)
#define for1(i, n) for(int i = 1; i < n; i++)
#define fori(s, e) for(int i = s; i < e; i++)
#define endl "\n"
typedef long long ll;
const int INF = 987654321;
const int MAX = 100;
const int N = 5e5;
int n;
vector<int> seg(2*N);
vector<int> idx_vec;
void insert(int val) {
int idx = N + val; seg[idx]++;
while(idx > 1) {
idx >>= 1;
seg[idx] = seg[idx << 1] + seg[idx << 1 | 1];
}
}
int get(int val) {
int ans = 0;
for(int l = N + val, r = 2 * N; l < r; l>>=1, r>>=1) {
if(l & 1) ans+=seg[l++];
if(r & 1) ans+=seg[--r];
}
return ans;
}
void solve() {
ll ans = 0;
for(int e: idx_vec) {
ans += get(e);
insert(e);
}
cout << ans;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n;
idx_vec.resize(n);
map<int, int> number_idx;
for0(i, n) {
int in; cin >> in;
number_idx[in] = i;
}
for0(i, n) {
int in; cin >> in;
idx_vec[number_idx[in]] = i;
}
solve();
}