Create sort.cpp

Changes

1 changed files (+161/-0)

• 2018/US Open/Platinum/sort.cpp (new)
  • @@ -0,0 +1,161 @@
    + #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> + #define init_io(pname) ifstream cin((string)pname+".in"); ofstream cout((string)pname+".out"); ios_base::sync_with_stdio(false); cin.tie(NULL) + #define FOR(i, a, b, in) for (int i = (a); i < (b); i += in) + #define REP(i, a, b) for (int i = (a); i < (b); i++) + #define RFOR(i, a, b, in) for (int i = (a) - 1; i >= (b); i -= in) + #define RREP(i, a, b) for (int i = (a) - 1; i >= (b); i--) + #define trav(a, x) for (auto& a : x) + #define mp make_pair + #define pb push_back + #define f first + #define s second + #define lb lower_bound + #define ub upper_bound + #define sz(x) (int)x.size() + #define all(x) begin(x), end(x) + #define rsz resize + #define mem(a, b) memset(a, (b), sizeof(a)) + using namespace std; + typedef string str; + typedef long long ll; + typedef long double ld; + typedef pair<int, int> ii; typedef pair<ll, ll> pl; typedef pair<ld, ld> pd; + typedef vector<int> vi; typedef vector<ll> vl; typedef vector<ld> vd; + typedef vector<ii> vii; typedef vector<pl> vpl; typedef vector<pd> vpd; + constexpr auto INF = (int)1e9; + constexpr auto LINF = (ll)1e18; + + template<typename T> class fenwick_tree { + private: vector<T> FT; + public: + fenwick_tree(int N) { FT.assign(N + 1, 0); } + void clear() { FT.assign(FT.size(), 0); } + void update(int x, T val) { if (x > 0) for (; x < FT.size(); x += x & -x) FT[x] += val; } + T query(int x) { T ret = 0; if (x > 0) for (; x > 0; x -= x & -x) ret += FT[x]; return ret; } + T query(int x, int y) { return query(y) - (x == 1 ? 0 : query(x - 1)); } + }; + + template< typename T > class seg_tree { + private: + int N; + vector<T> seg, tmp; + public: + seg_tree(int size) { + N = size; + seg.resize(4 * N, 0); + tmp.resize(4 * N, 0); + } + seg_tree(int size, T A[]) { + N = size; + seg.resize(4 * N); + tmp.resize(4 * N); + build(A); + } + seg_tree(vector<T>& A) { + N = A.size(); + seg.resize(4 * N); + tmp.resize(4 * N); + build(A); + } + void clear() { seg.assign(4 * N, 0); } + void pull(int n) { seg[n] = max(seg[n << 1], seg[n << 1 | 1]); } + void push(int l, int r, int n) { + seg[n] += tmp[n]; + if (l != r) tmp[n << 1] += tmp[n], tmp[n << 1 | 1] += tmp[n]; + tmp[n] = 0; + } + void build(T A[], int l = 0, int r = -1, int n = 1) { + if (r == -1) r = N - 1; + if (l == r) seg[n] = A[l]; + else { + int m = (l + r) >> 1; + build(A, l, m, n << 1), build(A, m + 1, r, n << 1 | 1); + pull(n); + } + } + void build(vector<T>& A, int l = 0, int r = -1, int n = 1) { + if (r == -1) r = N - 1; + if (l == r) seg[n] = A[l]; + else { + int m = (l + r) >> 1; + build(A, l, m, n << 1); + build(A, m + 1, r, n << 1 | 1); + pull(n); + } + } + void update(int x, T v, int l = 0, int r = -1, int n = 1) { + if (r == -1) r = N - 1; + if (l == r) seg[n] += v; + else { + int m = (l + r) >> 1; + x <= m ? update(x, v, l, m, n << 1) : update(x, v, m + 1, r, n << 1 | 1); + pull(n); + } + } + void update_range(int a, int b, T v, int l = 0, int r = -1, int n = 1) { + if (r == -1) r = N - 1; + push(n, l, r); + if (l > b || r < a) return; + if (l >= a && r <= b) { + tmp[n] = v; + push(n, l, r); + } + else { + int m = (l + r) >> 1; + update_range(a, b, v, l, m, n << 1), update_range(a, b, v, m + 1, r, n << 1 | 1); + pull(n); + } + } + T query(int a, int b, int l = 0, int r = -1, int n = 1) { + if (r == -1) r = N - 1; + if (l > b || r < a) return 0; + push(n, l, r); + if (l >= a && r <= b) return seg[n]; + int m = (l + r) >> 1; + return max(query(a, b, l, m, n << 1), query(a, b, m + 1, r, n << 1 | 1)); + } + }; + + int A[100005], C[100005] = { 0 }; + + int main() { + init_io("sort"); + + int N; + cin >> N; + for (int i = 0; i < N; i++) cin >> A[i]; + vector<ii> tmp; + for (int i = 0; i < N; i++) tmp.emplace_back(A[i], i); + sort(tmp.begin(), tmp.end()); + for (int i = 0; i < N; i++) A[tmp[i].second] = i; + + ll ans = 0; + fenwick_tree<int> FT(N); + seg_tree<int> seg(N); + for (int i = 0; i < N; i++) { + ans += FT.query(A[i], N - 1); + FT.update(A[i], 1); + } + for (int i = 0; i < N; i++) seg.update(A[i], i); + for (int i = 0; i < N; i++) { + int q = seg.query(0, A[i]); + if (i != q) C[i]++, C[q]--, ans++; + } + FT.clear(); + for (int i = N - 1; i >= 0; i--) { + ans += (ll)C[i] * FT.query(A[i], N - 1); + FT.update(A[i], 1); + } + cout << (ans ? ans : N) << endl; + }