Submission #925983

#	Time	Username	Problem	Language	Result	Execution time	Memory
925983		vjudge1	Collecting Mushrooms (NOI18_collectmushrooms)	C++17	100 / 100	17 ms	10052 KiB

mushrooms

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define ll long long
#define pb push_back
#define emb emplace_back
#define emc emplace
#define pii pair<int,int>
#define pll pair<ll,ll>
#define F first
#define S second
template <class type_key, class type_val>
using um = unordered_map<type_key, type_val>;
template <class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <class T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

struct coordinate {
	int x{}, y{};
	coordinate() = default;
	coordinate( int _x, int _y ) {
		x = _x, y = _y;
	}
};

signed main(void)
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);

	int n, m, d, k;
	cin >> n >> m >> d >> k;

	int pref[n+1][m+1];
	for( int i = 0; i <= n; i++ )
		pref[i][0] = pref[0][i] = 0;

	vector<coordinate> msh;
	for( int i = 1; i <= n; i ++ ) {
		for( int j = 1; j <= m; j++ ) {
			char c;
			cin >> c;
			pref[i][j] = pref[i-1][j] + pref[i][j-1] - pref[i-1][j-1];
			pref[i][j] += (c == 'S');
			if( c == 'M') {
				msh.pb(coordinate(i,j));
			}
		}
	}

	int ans = 0;
	for( int i = 0; i < msh.size(); i++ ) {
		int x1, y1, x2, y2;
		x1 = max(msh[i].x - d, 1);
		y1 = max(msh[i].y - d, 1);
		x2 = min(msh[i].x + d, n);
		y2 = min(msh[i].y + d, m);

		int cnt = pref[x2][y2] - pref[x2][y1-1] - pref[x1-1][y2] + pref[x1-1][y1-1];
		if( cnt >= k ) {
			ans++;
		}
	}
	cout << ans;

return 0;
}

Compilation message (stderr)

mushrooms.cpp: In function 'int main()':
mushrooms.cpp:56:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<coordinate>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |  for( int i = 0; i < msh.size(); i++ ) {
      |                  ~~^~~~~~~~~~~~

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