Submission #835599

#	Time	Username	Problem	Language	Result	Execution time	Memory
835599		mousebeaver	Seats (IOI18_seats)	C++14	25 / 100	4067 ms	73552 KiB

seats

    #include "seats.h"
    #include <bits/stdc++.h>
    #define pii pair<int, int>
    #define INF numeric_limits<int>::max()/2
    using namespace std;
     
    struct inf
    {
        int r1;
        int r2;
        int c1;
        int c2;
    };
     
    inf combine(inf a, inf b)
    {
        return {min(a.r1, b.r1), max(a.r2, b.r2), min(a.c1, b.c1), max(a.c2, b.c2)};
    }
     
    int area(inf dat)
    {
        return ((1+dat.r2-dat.r1)*(1+dat.c2-dat.c1));
    }
     
    int left(int i)
    {
        return 2*i;
    }
     
    int right(int i)
    {
        return 2*i+1;
    }
     
    int par(int i)
    {
        return i/2;
    }
     
    inf query(int i, vector<inf>& s, int a, int b, int l, int r)
    {
        if(l <= a && b <= r)
        {
            return s[i];
        }
        if(r < a || b < l)
        {
            return {INF, 0, INF, 0};
        }
        int mid = (a+b)/2;
        inf q1 = query(left(i), s, a, mid, l, r);
        inf q2 = query(right(i), s, mid+1, b, l, r);
        return {min(q1.r1, q2.r1), max(q1.r2, q2.r2), min(q1.c1, q2.c1), max(q1.c2, q2.c2)};
    }
     
    void update(int i, vector<inf>& s, inf val)
    {
        s[i] = val;
        i = par(i);
        while(i > 0)
        {
            s[i] = {min(s[left(i)].r1, s[right(i)].r1), max(s[left(i)].r2, s[right(i)].r2), min(s[left(i)].c1, s[right(i)].c1), max(s[left(i)].c2, s[right(i)].c2)};
            i = par(i);
        }
    }
     
    vector<inf> s(0);
    vector<pii> p(0);
    int segnodes = 1;
    int n = 1;
     
    void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) 
    {
        n = H*W;   
        while(2*n > segnodes)
        {
            segnodes *= 2;
        } 
     
        s.assign(segnodes, {INF, 0, INF, 0});
        p.assign(n, {-1, -1});
        for(int i = 0; i < n; i++)
        {
            s[i+segnodes/2] = {R[i], R[i], C[i], C[i]};
            p[i] = {R[i], C[i]};
        }
        for(int i = segnodes/2-1; i > 0; i--)
        {
            s[i] = {min(s[left(i)].r1, s[right(i)].r1), max(s[left(i)].r2, s[right(i)].r2), min(s[left(i)].c1, s[right(i)].c1), max(s[left(i)].c2, s[right(i)].c2)};
        }
    }
     
    int swap_seats(int d, int b) 
    {
        swap(p[d], p[b]);
        update(segnodes/2+d, s, {p[d].first, p[d].first, p[d].second, p[d].second});
        update(segnodes/2+b, s, {p[b].first, p[b].first, p[b].second, p[b].second});
     
        int output = 1;
        int a = 1;
        
        while(a < n)
        {
            int i = segnodes/2;
            inf dat = s[i];
            while(area(dat) <= a)
            {
                i = par(i);
                dat = s[i];
            }
            dat = s[left(i)];
            i = right(i);
            //Now, we are in the lowest node that contains enough area! => Going back down
            while(left(i) < segnodes)
            {
                if(area(combine(s[left(i)], dat)) > a)
                {
                    i = left(i);
                }
                else
                {
                    dat = combine(dat, s[left(i)]);
                    i = right(i);
                }
            }
            dat = combine(dat, s[i]);
            a = area(dat);
            output += (a == area(query(1, s, 1, segnodes/2, 1, a)));
        }
        return output;
    }

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