Submission #1311661

#	Time	Username	Problem	Language	Result	Execution time	Memory
1311661		samarthkulkarni	Collecting Mushrooms (NOI18_collectmushrooms)	C++20	100 / 100	218 ms	71632 KiB

mushrooms

#include <bits/stdc++.h>
using namespace std;

using ll = long long;
#define vi vector<long long>
#define all(x) x.begin(), x.end()
#define endl "\n"
#define pr pair<ll, ll>
#define ff first
#define ss second

void solution();
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    solution();
    return 0;
}


ll r, c, d, k;

struct SegTree {
	vi lzy, tree;
	ll n;
	SegTree () {
		n = c;
		lzy.resize(4*n);
		tree.resize(4*n);
	}

	void push(int id, int l, int r) {
		if (lzy[id] == 0) return;
		tree[id] += lzy[id]*(r-l+1);

		if (l != r) {
			lzy[2*id] += lzy[id];
			lzy[2*id+1] += lzy[id];
		}

		lzy[id] = 0;
	}

	void update(int id, int l, int r, int L, int R, int val = 1) {
		push(id, l, r);
		if (L > r || l > R) return;
		if (L <= l && R >= r) {
			lzy[id] += val;
			push(id, l, r);
			return;
		}
		int mid = (l + r)/2;
		update(2*id, l, mid, L, R, val);
		update(2*id+1, mid+1, r, L, R, val);
		tree[id] = tree[2*id] + tree[2*id+1];
	}

	ll query(int id, int l, int r, int pos) {
		push(id, l, r);
		if (pos < l || pos > r) return 0;
		if (l  == r) return tree[id];
		int mid = (l + r)/2;

		return query(2*id, l, mid, pos) + query(2*id+1, mid+1, r, pos);
	}


	void update(int l, int r, int val = 1) {
		l = max(0, l);
		r = min(r, int(c-1));
		update(1, 0, n-1, l, r, val);
	}

	ll query(int pos) {return query(1, 0, n-1, pos);}
};


void ad(pr p, vector<SegTree> &m) {
	int t = max(0ll, p.ff-d);
	int b = min(r-1, p.ff+d)+1;
	int lf = max(0ll, p.ss - d);
	int ri = min(c-1, p.ss+d);

	m[t].update(lf, ri);
	m[b].update(lf, ri, -1);
}

void solution() {
	
	cin >> r >> c >> d >> k;

	vector<string> a(r);

	for (string &z : a) cin >> z;


	vector<SegTree> m(r+1);
		

	for (int i = 0; i < r; i++) {
		for (int j = 0; j < c; j++) {
			if (a[i][j] == 'S') {
				ad({i, j}, m);
			}
		}
	}



	vector<vi> arr(r, vi(c));

	for (int i = 0; i < r; i++) {
		for (int j = 0; j < c; j++) {
			arr[i][j] = m[i].query(j);
		}
	}

	for (int j = 0; j < c; j++) {
		for (int i = 1; i < r; i++) {
			arr[i][j] += arr[i-1][j];
		}
	}




	ll ans = 0;
	for (int i = 0; i < r; i++) {
		for (int j = 0; j < c; j++) {
			if (a[i][j] == 'M' && arr[i][j] >= k) ans++; 
		}
	}
	cout << ans << endl;





}

• Subtask 1: 9 / 9
• Subtask 2: 10 / 10
• Subtask 3: 18 / 18
• Subtask 4: 23 / 23
• Subtask 5: 19 / 19
• Subtask 6: 21 / 21