Submission #284267

#	Time	Username	Problem	Language	Result	Execution time	Memory
284267		YJU	Dango Maker (JOI18_dango_maker)	C++14	100 / 100	488 ms	181536 KiB

dango_maker

#include<bits/stdc++.h>
#pragma GCC optimize("unroll-loops,no-stack-protector")
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pll;
const ll MOD=1e9+7;
const ll MOD2=998244353;
const ll N=3e3+5;
const ld pi=3.14159265359;
const ll INF=(1LL<<60);
#define SQ(i) ((i)*(i))
#define REP(i,n) for(ll i=0;i<n;i++)
#define REP1(i,n) for(ll i=1;i<=n;i++)
#define pb push_back
#define mp make_pair
#define X first
#define Y second
#define setp setprecision
#define lwb lower_bound
#define SZ(_a) (ll)_a.size()

char c[N][N];
ll dp[N][3],n,m,T[N][N],ans;
vector<ll> D[2*N];

bool valid(ll xa,ll ya,ll xb,ll yb){
	if(xa>xb)swap(xa,xb);
	if(ya>yb)swap(ya,yb);
	ll xm=(xa+xb)/2,ym=(ya+yb)/2;
	if(xa<0||xb>=n||ya<0||yb>=m||c[xm][ym]!='G')return 0;
	if(ya==yb){
		return ((c[xa][ym]=='R'&&c[xb][ym]=='W'));
	}else{
		return ((c[xm][ya]=='R'&&c[xm][yb]=='W'));
	}
}

ll CAL(ll id){
	memset(dp,0,sizeof(dp));
	REP(i,SZ(D[id])){
		dp[i+1][0]=max(dp[i][0],max(dp[i][1],dp[i][2]));
		if(D[id][i]&1)dp[i+1][1]=max(dp[i][0],dp[i][1])+1;
		if(D[id][i]&2)dp[i+1][2]=max(dp[i][0],dp[i][2])+1;
	}
	return max(dp[SZ(D[id])][0],max(dp[SZ(D[id])][1],dp[SZ(D[id])][2]));
}

int main(){
	ios_base::sync_with_stdio(0);cin.tie(0);
	cin>>n>>m;
	REP(i,n)REP(j,m){
		cin>>c[i][j];
	}
	REP(i,n)REP(j,m){
		ll nd=i*m+j;
		if(c[i][j]=='G'){
			if(valid(i-1,j,i+1,j))T[i][j]|=1;
			if(valid(i,j-1,i,j+1))T[i][j]|=2;
		}
		D[i+j].pb(T[i][j]);
	}
	REP(i,n+m-1){
		ans+=CAL(i);
	}
	cout<<ans<<"\n";
	return 0;
}

Compilation message (stderr)

dango_maker.cpp: In function 'int main()':
dango_maker.cpp:56:6: warning: unused variable 'nd' [-Wunused-variable]
   56 |   ll nd=i*m+j;
      |      ^~

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