Create mincross.cpp

Changes

1 changed files (+57/-0)

• 2017/February/Platinum/mincross.cpp (new)
  • @@ -0,0 +1,57 @@
    + #include <algorithm> + #include <iostream> + #include <fstream> + #include <string> + #include <vector> + #include <queue> + #include <set> + #include <map> + #include <unordered_set> + #include <unordered_map> + #include <cmath> + #include <cstring> + using namespace std; + typedef long long ll; + typedef pair<int, int> ii; + typedef vector<int> vi; + typedef vector<ii> vii; + constexpr auto INF = (ll)1e18; + + class fenwick_tree { + private: vector<int> FT; + public: + fenwick_tree(int N) { FT.assign(N + 1, 0); } + void update(int x, int val) { for (; x < FT.size(); x += x & -x) FT[x] += val; } + int query(int x) { int ret = 0; for (; x > 0; x -= x & -x) ret += FT[x]; return ret; } + int query(int x, int y) { return query(y) - (x == 1 ? 0 : query(x - 1)); } + }; + + int A[100005], B[100005], RA[100005], RB[100005]; + + int main() { + ifstream cin("mincross.in"); + ofstream cout("mincross.out"); + + int N; + cin >> N; + for (int i = 0; i < N; ++i) cin >> A[i]; + for (int i = 0; i < N; ++i) cin >> B[i]; + for (int i = 0; i < N; ++i) RA[A[i]] = i + 1; + for (int i = 0; i < N; ++i) RB[B[i]] = i + 1; + + fenwick_tree FT(N); + ll cnt = 0, ans = INF; + for (int i = 0; i < N; ++i) { + cnt += FT.query(RA[B[i]], N); + FT.update(RA[B[i]], 1); + } + for (int i = 0; i < N; ++i) { + cnt += N - 2 * RA[B[i]] + 1; + ans = min(cnt, ans); + } + for (int i = 0; i < N; ++i) { + cnt += N - 2 * RB[A[i]] + 1; + ans = min(cnt, ans); + } + cout << ans << endl; + }