Submission #1028885

#	Time	Username	Problem	Language	Result	Execution time	Memory
1028885		onbert	Rectangles (IOI19_rect)	C++17	13 / 100	4432 ms	620372 KiB

rect

#include "rect.h"
#include <bits/stdc++.h>
using namespace std;
#define ss short
#define ll long long
struct range {
    ss r, mx;
};
bool cmp0(range &a, range &b) {return a.r > b.r;}
bool cmp1(range &a, range &b) {return a.mx > b.mx;}
const int maxn = 2505, INF = 2505;
int n, m;
vector<vector<vector<pair<ss,ss>>>> pos[2];
vector<vector<vector<range>>> start[2];

ss fen[maxn];
void update(int id, int val) {
    while (id<maxn) {
        fen[id] += val;
        id += (id & -id);
    }
}
int qry(int id) {
    int val = 0;
    while (id >= 1) {
        val += fen[id];
        id -= (id & -id);
    }
    return val;
}

pair<ss,ss> seg[10005];
void build(int id, int l, int r) {
    seg[id] = {INF, -1};
    if (l==r) return;
    int mid = (l+r)/2;
    build(id*2, l, mid); build(id*2+1, mid+1, r);
}
void update1(int id, int l, int r, int target, int val) {
    if (r<target || target<l) return;
    if (l==r) {
        seg[id] = {val, val};
        return;
    }
    int mid = (l+r)/2;
    update1(id*2, l, mid, target, val); update1(id*2+1, mid+1, r, target, val);
    seg[id] = {min(seg[id*2].first, seg[id*2+1].first), max(seg[id*2].second, seg[id*2+1].second)};
}
ss qry1(int id, int l, int r, int findl, int findr, int t) {
    if (r<findl || findr<l) {
        if (t==0) return INF;
        else return -1;
    }
    if (findl<=l && r<=findr) {
        if (t==0) return seg[id].first;
        else return seg[id].second;
    }
    int mid = (l+r)/2;
    int lhs = qry1(id*2, l, mid, findl, findr, t), rhs = qry1(id*2+1, mid+1, r, findl, findr, t);
    if (t==0) return min(lhs, rhs);
    else return max(lhs, rhs);
}

long long count_rectangles(vector<vector<int32_t>> a) {
	n = a.size(), m = a[0].size();
    pos[0].resize(m);
    for (int i=0;i<m;i++) pos[0][i].resize(m - i);
    pos[1].resize(n);
    for (int i=0;i<n;i++) pos[1][i].resize(n - i);
    start[0].resize(n); start[1].resize(n);
    for (int i=0;i<n;i++) start[0][i].resize(m), start[1][i].resize(m);

    vector<pair<ss,ss>> cur;
    vector<ss> temp;
    for (int i=0;i<n;i++) {
        cur.clear();
        for (int j=0;j<m;j++) cur.push_back({a[i][j], j});
        sort(cur.rbegin(), cur.rend());
        build(1, 0, m-1);
        temp.clear();
        for (int j=0;j<m;j++) {
            auto [val, id] = cur[j];
            if (j>0 && val!=cur[j-1].first) {
                for (int x:temp) update1(1, 0, m-1, x, x);
                temp.clear();
            }
            ss l = qry1(1, 0, m-1, 0, id, 1), r = qry1(1, 0, m-1, id, m-1, 0);
            if (l!=-1 && r!=INF) {
                l++, r--;
                if (pos[0][l][r-l].size()==0 || pos[0][l][r-l].back().first!=i) {
                    pos[0][l][r-l].push_back({i, -1});
                    start[0][i][l].push_back({r, -1});
                }
            }
            temp.push_back(id);
        }
    }

    for (int j=0;j<m;j++) {
        cur.clear();
        for (int i=0;i<n;i++) cur.push_back({a[i][j], i});
        sort(cur.rbegin(), cur.rend());
        build(1, 0, n-1);
        temp.clear();
        for (int i=0;i<n;i++) {
            auto [val, id] = cur[i];
            if (i>0 && val!=cur[i-1].first) {
                for (int x:temp) update1(1, 0, n-1, x, x);
                temp.clear();
            }
            ss l = qry1(1, 0, n-1, 0, id, 1), r = qry1(1, 0, n-1, id, n-1, 0);
            if (l!=-1 && r!=INF) {
                l++, r--;
                if (pos[1][l][r-l].size()==0 || pos[1][l][r-l].back().first!=j) {
                    pos[1][l][r-l].push_back({j, -1});
                    start[1][l][j].push_back({r, -1});
                }
            }
            temp.push_back(id);
        }
    }

    for (int I=0;I<=1;I++) {
        int nn = m;
        if (I==1) nn = n;
        for (int l=0;l<nn;l++) for (int r=l;r<nn;r++) {
            sort(pos[I][l][r-l].begin(), pos[I][l][r-l].end());
            int sz = pos[I][l][r-l].size();
            for (int i=sz-1;i>=0;i--) {
                if (i==sz-1 || pos[I][l][r-l][i+1].first!=pos[I][l][r-l][i].first+1) pos[I][l][r-l][i].second = pos[I][l][r-l][i].first;
                else pos[I][l][r-l][i].second = pos[I][l][r-l][i+1].second;
            }
        }
    }
    for (int I=0;I<=1;I++) {
        for (int i=0;i<n;i++) for (int j=0;j<m;j++) {
            for (auto &[r, mx]:start[I][i][j]) {
                ss x = j, y = i;
                if (I==1) x = i, y = j;
                mx = (*lower_bound(pos[I][x][r-x].begin(), pos[I][x][r-x].end(), make_pair(y, (ss)-1))).second;
            }
        }
    }
    ll ans = 0;
    vector<int> LOG;
    for (int i=1;i<n-1;i++) for (int j=1;j<m-1;j++) {
        sort(start[0][i][j].begin(), start[0][i][j].end(), cmp0);
        sort(start[1][i][j].begin(), start[1][i][j].end(), cmp1);
        int pt = -1;
        LOG.clear();
        for (auto [r, mx]:start[0][i][j]) {
            while (pt+1 < start[1][i][j].size() && start[1][i][j][pt+1].mx >= r) {
                pt++;
                update(start[1][i][j][pt].r, 1);
                LOG.push_back(start[1][i][j][pt].r);
            }
            ans += qry(mx);
        }
        for (int x:LOG) update(x, -1);
    }
    return ans;
}

Compilation message (stderr)

rect.cpp: In function 'long long int count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:152:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<range>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  152 |             while (pt+1 < start[1][i][j].size() && start[1][i][j][pt+1].mx >= r) {
      |                    ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 7
• Subtask 3: 0 / 12
• Subtask 4: 0 / 22
• Subtask 5: 0 / 10
• Subtask 6: 13 / 13
• Subtask 7: 0 / 28