Submission #1111844

#	Time	Username	Problem	Language	Result	Execution time	Memory
1111844		steveonalex	Seats (IOI18_seats)	C++17	33 / 100	854 ms	91852 KiB

seats

#include <bits/stdc++.h>
#include "seats.h"

using namespace std;

typedef long long ll;
typedef unsigned int ul;
typedef unsigned long long ull;

#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()

ll gcd(ll a, ll b){return __gcd(a, b);}
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}

ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T the_array_itself, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: the_array_itself) out << item << separator;
        out << finish;
    }

template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

struct SegmentTree{
    int n;
    vector<pair<int,int>> a;
    vector<int> lazy;

    SegmentTree(int _n){
        n = _n;
        a.resize(n * 4 + 4);
        lazy.resize(n * 4 + 4);

        build_tree(0, n-1, 1);
    }

    pair<int, int> combine(pair<int, int> a, pair<int, int> b){
        pair<int, int> c = {min(a.first, b.first), 0};
        if (a.first == c.first) c.second += a.second;
        if (b.first == c.first) c.second += b.second;
        return c;
    }

    void build_tree(int l, int r, int id){
        if (l == r){a[id] = {0, 1}; return;}
        int mid = (l + r) >> 1;
        build_tree(l, mid, id * 2); build_tree(mid + 1, r, id * 2 + 1);
        a[id] = combine(a[id * 2], a[id * 2 + 1]);
    }

    void apply(int id, int val){
        a[id].first += val;
        lazy[id] += val;
    }

    void down(int id){
        apply(id * 2, lazy[id]); apply(id * 2 + 1, lazy[id]);
        lazy[id] = 0;
    }

    void update(int u, int v, int val, int l, int r, int id){
        if (u <= l && r <= v){
            apply(id, val);
            return;
        }
        down(id);
        int mid = (l + r) >> 1;
        if (u <= mid) update(u, v, val, l, mid, id * 2);
        if (v > mid) update(u, v, val, mid + 1, r, id * 2 + 1);
        a[id] = combine(a[id * 2], a[id * 2 + 1]);
    }

    void update(int l, int r, int val){
        update(l, r, val, 0, n-1, 1);
    }

    int get(){
        return a[1].second;
    }
};

const int INF = 1e9 + 69;

int h, w;
vector<int> r, c;
vector<int> a;
SegmentTree st(1);

void give_initial_chart(int H, int W, vector<int> R, vector<int> C) {
    h = H, w = W;
    r = R; c = C;
    if (h != 1) exit(1);

    st = SegmentTree(w);
    a.resize(w);
    for(int i = 0; i < w; ++i) {
        a[c[i]] = i;
        st.update(i, i, i + 1);
    }
    for(int i = 0; i < w; ++i){
        if (i > 0 && a[i-1] < a[i]) st.update(a[i], w - 1, -1);
        if (i + 1 < w && a[i+1] < a[i]) st.update(a[i], w - 1, -1);
    }
}

void update(int i, int val){
    if (i - 1 >= 0 && a[i-1] != -1){
        st.update(max(a[i], a[i-1]), w-1, -val);
    }
    if (i + 1 < w && a[i+1] != -1){
        st.update(max(a[i], a[i+1]), w-1, -val);
    }
}

int swap_seats(int x, int y) {
    int p1 = c[x], p2 = c[y];
    swap(c[x], c[y]);

    update(p1, -1); 
    update(p2, -1);
    swap(a[p1], a[p2]);
    update(p2, 1);
    update(p1, 1); 

    return st.get();
}


// int main(void){
//     ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

//     clock_t start = clock();

//     int n, m;cin >> n >> m;
//     vector<int> r(n * m), c(n*m);
//     for(int i = 0; i < n*m; ++i) cin >> r[i] >> c[i];

//     give_initial_chart(n, m, r, c);
//     int q; cin >> q;
//     while(q--){
//         int u, v; cin >> u >> v;
//         cout << swap_seats(u, v) << "\n";
//     }

//     cerr << "Time elapsed: " << clock() - start << " ms!\n";

//     return 0;
// }

• Subtask 1: 0 / 5
• Subtask 2: 0 / 6
• Subtask 3: 0 / 20
• Subtask 4: 0 / 6
• Subtask 5: 33 / 33
• Subtask 6: 0 / 30