Submission #764205

#	Time	Username	Problem	Language	Result	Execution time	Memory
764205		qwerasdfzxcl	Seats (IOI18_seats)	C++17	100 / 100	495 ms	176700 KiB

seats

#include "seats.h"
#include <bits/stdc++.h>
 
using namespace std;
typedef long long ll;
const int INF = 1e9+100;
 
struct Node{
    int prf, sum, cnt;
    Node(){}
    Node(int _prf, int _sum, int _cnt): prf(_prf), sum(_sum), cnt(_cnt) {}
    Node operator + (const Node &N) const{
        int tmp = sum + N.prf;
        if (tmp < prf) return Node(tmp, sum + N.sum, N.cnt);
        if (tmp > prf) return Node(prf, sum + N.sum, cnt);
        return Node(prf, sum + N.sum, cnt + N.cnt);
    }
};
 
struct Seg{
    Node tree[2202000];
    int sz;
    void init(int n, int a[]){
        sz = n;
        for (int i=sz;i<sz*2;i++) tree[i] = Node(a[i-sz], a[i-sz], 1);
        for (int i=sz-1;i;i--) tree[i] = tree[i<<1] + tree[i<<1|1];
    }
    void update(int p, int x){
        p += sz;
        if (tree[p].prf==x) return;
        tree[p] = Node(x, x, 1);
        for (p>>=1;p;p>>=1) tree[p] = tree[p<<1] + tree[p<<1|1];
    }
    Node query(int l, int r){
        Node retl(INF, 0, 0), retr(INF, 0, 0);
        ++r;
        for (l+=sz, r+=sz;l<r;l>>=1, r>>=1){
            if (l&1) retl = retl + tree[l++];
            if (r&1) retr = tree[--r] + retr;
        }
        return retl + retr;
    }
}tree;
 
vector<vector<int>> a, chk;
int n, m, d[1001000], X[1001000], Y[1001000], dx[4] = {0, 0, 1, 1}, dy[4] = {0, 1, 0, 1};
 
void calc(int x, int y, int o){
    pair<int, int> adj[4];
    for (int k=0;k<4;k++){
        adj[k] = {a[x+dx[k]][y+dy[k]], k};
    }
    sort(adj, adj+4);
 
    int tmp[5] = {0};
    tmp[1] = 1;
    tmp[2] = (adj[0].second+adj[1].second==3)?1:0;
    tmp[3] = 1;
    tmp[4] = 0;
 
    for (int i=1;i<=4;i++) if (adj[i-1].first < INF){
        if (o) d[adj[i-1].first] += (tmp[i] - tmp[i-1]);
        else d[adj[i-1].first] -= (tmp[i]-tmp[i-1]);
    }
}
 
void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) {
    n = H, m = W;
    a.resize(n+2, vector<int>(m+2, INF));
    chk.resize(n+2, vector<int>(m+2, 0));
    for (int i=1;i<=n*m;i++){
        a[R[i-1] + 1][C[i-1] + 1] = i;
        X[i] = R[i-1] + 1;
        Y[i] = C[i-1] + 1;
    }
 
    for (int i=0;i<=n;i++){
        for (int j=0;j<=m;j++){
            calc(i, j, 1);
        }
    }
 
    tree.init(n*m+1, d);
    //for (int i=1;i<=n*m;i++) tree.update(i, d[i]);
}
 
int swap_seats(int A, int B) {
    ++A, ++B;
    int C[2] = {A, B};
    for (auto p:C){
        for (int i=-1;i<=0;i++){
            for (int j=-1;j<=0;j++) if (!chk[X[p]+i][Y[p]+j]){
                calc(X[p]+i, Y[p]+j, 0);
                chk[X[p]+i][Y[p]+j] = 1;
            }
        }
    }
 
    swap(a[X[A]][Y[A]], a[X[B]][Y[B]]);
    swap(X[A], X[B]);
    swap(Y[A], Y[B]);
 
    for (auto p:C){
        for (int i=-1;i<=0;i++){
            for (int j=-1;j<=0;j++) if (chk[X[p]+i][Y[p]+j]){
                calc(X[p]+i, Y[p]+j, 1);
                chk[X[p]+i][Y[p]+j] = 0;
            }
        }
    }
 
    for (auto p:C){
        for (int i=-1;i<=1;i++){
            for (int j=-1;j<=1;j++) if (a[X[p]+i][Y[p]+j] < INF){
                tree.update(a[X[p]+i][Y[p]+j], d[a[X[p]+i][Y[p]+j]]);
            }
        }
    }
 
    auto N = tree.query(1, n*m);
    assert(N.prf==4);
    return N.cnt;
}

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