Submission #835608

#	Time	Username	Problem	Language	Result	Execution time	Memory
835608		mousebeaver	Seats (IOI18_seats)	C++14	37 / 100	4040 ms	80808 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;
        bool possible;
    };
     
    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);
    vector<inf> a(0);
    int segnodes = 1;
    int counter = 1;
    int n = 1;
    bool sub3 = false;
     
    void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) 
    {
        if(H <= 1000 && W <= 1000)
        {
            sub3 = true;
        }

        if(sub3)
        {
            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)};
            }
        }
        else
        {
            n = H*W;
            for(int i = 0; i < n; i++)
            {
                p.push_back({R[i], C[i]});
            }
        
            a = {{p[0].first, p[0].first, p[0].second, p[0].second, true}};
            for(int i = 1; i < n; i++)
            {
                a.push_back(a.back());
                a.back().r1 = min(a.back().r1, p[i].first);
                a.back().r2 = max(a.back().r2, p[i].first);
                a.back().c1 = min(a.back().c1, p[i].second);
                a.back().c2 = max(a.back().c2, p[i].second);
                a.back().possible = ((1+a.back().r2-a.back().r1)*(1+a.back().c2-a.back().c1) == i+1);
                counter += a.back().possible;
            }
        }
    }
     
    int swap_seats(int d, int b) 
    {
        if(sub3)
        {

            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 ar = 1;
            
            while(ar < n)
            {
                int i = segnodes/2;
                inf dat = s[i];
                while(area(dat) <= ar)
                {
                    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)) > ar)
                    {
                        i = left(i);
                    }
                    else
                    {
                        dat = combine(dat, s[left(i)]);
                        i = right(i);
                    }
                }
                dat = combine(dat, s[i]);
                ar = area(dat);
                output += (ar == area(query(1, s, 1, segnodes/2, 1, ar)));
            }
            return output;
        }
        else
        {
            if(d > b)
            {
                swap(d, b);
            }
            swap(p[d], p[b]);
        
            for(int i = d; i <= b; i++)
            {
                counter -= a[i].possible;
                if(i == 0)
                {
                    a[i] = {p[0].first, p[0].first, p[0].second, p[0].second, true};
                }
                else
                {
                    a[i] = a[i-1];
                }
                a[i].r1 = min(a[i].r1, p[i].first);
                a[i].r2 = max(a[i].r2, p[i].first);
                a[i].c1 = min(a[i].c1, p[i].second);
                a[i].c2 = max(a[i].c2, p[i].second);
                a[i].possible = ((1+a[i].r2-a[i].r1)*(1+a[i].c2-a[i].c1) == i+1);
                counter += a[i].possible;
            }
        
            return counter;
        }
    }

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