Submission #364437

#	Time	Username	Problem	Language	Result	Execution time	Memory
364437		saarang123	Rectangles (IOI19_rect)	C++17	37 / 100	5111 ms	539136 KiB

rect

#include <bits/stdc++.h>
using namespace std;
const int N = 2502;
 
template<bool returnMax, bool returnIndex>
struct SparseTable {
    int n, k;
    vector<int> a;
    vector<vector<int>> st;
    void init(vector<int> a) {
        this->a = a;
        n = (int) a.size();
        k = lg(n);
        st.assign(n + 1, vector<int>(k + 1));
        build();
    }
    int lg(int x) { return 31 - __builtin_clz(x); }
    int merge(int x, int y) {
        if (returnMax) return a[x] >= a[y] ? x : y;
        return a[x] < a[y] ? x : y;
    }
    void build() {
        for (int i = 0; i < n; i++) st[i][0] = i;
        for (int j = 1; j <= k; j++)
            for (int i = 0; i + (1 << j) - 1 < n; i++)
                st[i][j] = merge(st[i][j - 1], st[i + (1 << (j - 1))][j - 1]);
    }
    int query(int l, int r) {
    	l--; r--;
        int j = lg(r - l + 1);
        int idx = merge(st[l][j], st[r - (1 << j) + 1][j]);
        return (returnIndex ? idx : a[idx]);
    }
};
 
long long count_rectangles(vector<vector<int>> a) {
	int n = a.size(), m = a[0].size();
	vector<SparseTable<1, 0>> rows(n);
	for(int i = 0; i < n; i++) {
		rows[i].init(a[i]);
	}
	vector<SparseTable<1, 0>> columns(m);
	for(int j = 0; j < m; j++) {
		vector<int> t;
		for(int i = 0; i < n; i++)
			t.push_back(a[i][j]);
		columns[j].init(t);
	}
	long long ans = 0;
	for(int r1 = 1; r1 < n - 1; r1++) {
		for(int c1 = 1; c1 < m - 1; c1++) {
			for(int r2 = r1; r2 < n - 1; r2++) {
				for(int c2 = c1; c2 < m - 1; c2++) {
					//if(r1 == r2 && c1 == c2) continue;
					bool flag = 1;
					for(int i = r1; i <= r2; i++) {
						flag &= (rows[i].query(c1 + 1, c2 + 1) < min(a[i][c1 - 1], a[i][c2 + 1]));
                      	if(!flag) break;
                    }
					for(int i = c1; i <= c2; i++) {
                      	if(!flag) break;
						flag &= (columns[i].query(r1 + 1, r2 + 1) < min(a[r1 - 1][i], a[r2 + 1][i]));
                    }
					ans += flag;
				}
			}
		}
	}
	return ans;
}

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