Submission #951389

#	Time	Username	Problem	Language	Result	Execution time	Memory
951389		starchan	Dango Maker (JOI18_dango_maker)	C++17	100 / 100	249 ms	159804 KiB

dango_maker

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define in pair<int, int>
#define f first
#define s second
#define pb push_back
#define pob pop_back
#define INF (int)1e17
#define fast() ios_base::sync_with_stdio(false); cin.tie(NULL)
const int SMX = 3e3+5;
char grid[SMX][SMX];
int gud[SMX][SMX][2];//automatically set to zero anyway
int solve(int DIAG, int l, int r)
{
	int n = r-l+1;
	int dp[n+1][2];
	dp[0][0] = dp[0][1] = 0;
	dp[1][0] = gud[l][DIAG-l][0]; dp[1][1] = gud[l][DIAG-l][1];
	for(int i = 2; i <= n; i++)
	{
		dp[i][0] = gud[l-1+i][DIAG-l+1-i][0]+max(dp[i-1][0], max(dp[i-2][0], dp[i-2][1]));
		dp[i][1] = gud[l-1+i][DIAG-l+1-i][1]+max(dp[i-1][1], max(dp[i-2][0], dp[i-2][1]));
	}
	int ans = 0;
	for(int i = 0; i <= n; i++)
		ans = max(ans, max(dp[i][0], dp[i][1]));
	return ans;
}
signed main()
{
	fast();
	int n, m;
	cin >> n >> m;
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < m; j++)
			cin >> grid[i][j];
	}
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < m; j++)
		{
			if(grid[i][j] != 'G')
				continue;
			if((i > 0) && (i < (n-1)) && (grid[i-1][j] == 'R') && (grid[i+1][j] == 'W'))
				gud[i][j][0] = 1;
			if((j > 0) && (j < (m-1)) && (grid[i][j-1] == 'R') && (grid[i][j+1] == 'W'))
				gud[i][j][1] = 1;
		}
	}
	int ans = 0;
	int l[n+m-1], r[n+m-1];
	for(int i = 0; i < n; i++)
	{
		for(int j = 0; j < m; j++)
			r[i+j] = i;
	}
	for(int i = n-1; i >= 0; i--)
	{
		for(int j = 0; j < m; j++)
			l[i+j] = i;
	}
	for(int DIAG = 0; DIAG <= n+m-2; DIAG++)
		ans+=solve(DIAG, l[DIAG], r[DIAG]);
	cout << ans << "\n";
	return 0;
}	

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