Submission #303911

#	Time	Username	Problem	Language	Result	Execution time	Memory
303911		pit4h	Dango Maker (JOI18_dango_maker)	C++14	100 / 100	502 ms	117580 KiB

dango_maker

#include<bits/stdc++.h>
using namespace std;
const int N = 3001;
int n, m, nr;
int matched[N * N], vis[N * N];
int iter;
bool horiz[N][N], vert[N][N];
string tab[N];
vector<int> vx = {0, -1, -2}, vy = {0, 1, 2};
bool ok(int x, int y) {
	if(x>=0 && y<m && horiz[x][y]) return true;
	return false;
}
int convert(int x, int y) {
	return x*m + y;
}
bool match(int x) {
	vis[x] = iter;
	for(int i=0; i<3; ++i) {
		int X = x/m + vx[i], Y = x%m + vy[i];
		int rep = convert(X, Y);
		if(ok(X, Y) && matched[rep]==-1) {
			matched[rep] = x;
			return true;
		}
	}
	for(int i=0; i<3; ++i) {
		int X = x/m + vx[i], Y = x%m + vy[i];
		int rep = convert(X, Y);
		if(ok(X, Y) && vis[matched[rep]] != iter && match(matched[rep])) {
			matched[rep] = x;
			return true;
		}
	}
	return false;
}
int main() {
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	cin>>n>>m;
	for(int i=0; i<n; ++i) {
		cin>>tab[i];
	}
	int sz = 0;
	vector<int> cand;
	for(int i=0; i<n; ++i) { // left - right
		for(int j=0; j+2<m; ++j) {
			if(tab[i][j] == 'R' && tab[i][j+1] == 'G' && tab[i][j+2] == 'W') {
				vert[i][j] = 1;
				sz++;
				cand.push_back(convert(i, j));
			}
		}
	}
	for(int i=0; i+2<n; ++i) { // top - bottom 
		for(int j=0; j<m; ++j) {
			if(tab[i][j] == 'R' && tab[i+1][j] == 'G' && tab[i+2][j] == 'W') {
				horiz[i][j] = 1;
				nr++;
			}
		}
	}
	for(int i=0; i<n*m; ++i) {
		matched[i] = -1;
	}
	int ans = 0;
	for(int i=0; i<sz; ++i) {
		iter++;
		match(cand[i]);
	}
	for(int i=0; i<n*m; ++i) {
		if(matched[i] != -1) {
			ans++;
		}
	}
	cout<<nr + sz - ans;
}

• Subtask 1: 13 / 13
• Subtask 2: 20 / 20
• Subtask 3: 67 / 67