Submission #1274162

#	Time	Username	Problem	Language	Result	Execution time	Memory
1274162		trinm01	Dango Maker (JOI18_dango_maker)	C++20	100 / 100	290 ms	9676 KiB

dango_maker

// #pragma GCC optimize("O3")
// #pragma GCC optimization("Ofast,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
using namespace std;

#define int long long 
#define ll long long
#define FOR(i, l, r) for (int i = (l); i <= (r); i++)
#define FOD(i, r, l) for (int i = (r); i >= (l); i--)
#define fi first
#define se second
#define pii pair<int, int>

const ll mod = 1e9 + 7;
const int MAXN = 3e3 + 5;
const ll oo = 1e18 + 7;  
const int base = 10;

int m, n;
char a[MAXN][MAXN];

int chk1(int x, int y){
	if(x-1<1 || x+1>m){
		return 0;
	}
	return (a[x-1][y]=='R' && a[x][y]=='G' && a[x+1][y]=='W');
}
int chk2(int x, int y){
	if(y-1<1 || y+1>n){
		return 0;
	}
	return (a[x][y-1]=='R' && a[x][y]=='G' && a[x][y+1]=='W');
}

vector<pii> vec;
int f[2*MAXN][3];
int dp(int i, int t){
	if(i>(int)vec.size()-1){
		return 0;
	}
	if(f[i][t]!=-1){
		return f[i][t];
	}
	
	int x=vec[i].fi, y=vec[i].se;
	int ans=0;
	ans=max(ans, dp(i+1, 0));
	if(chk1(x, y) && t!=2){
		ans=max(ans, dp(i+1, 1)+1);
	}
	if(chk2(x, y) && t!=1){
		ans=max(ans, dp(i+1, 2)+1);
	}
	return f[i][t]=ans;
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    
    
    // freopen("test.txt", "r", stdin);
    // freopen("o2.out", "w", stdout);

    if(fopen(".inp", "r")){
        freopen(".inp", "r", stdin);
        freopen(".out", "w", stdout);
    }

    cin >> m >> n;
    FOR(i, 1, m){
    	FOR(j, 1, n){
    		cin >> a[i][j];
    	}
    }
    
    int ans=0;
    FOR(id, 2, m+n){
    	int x, y;
    	if(id<=n+1){
    		x=1;
    		y=id-x;
    	}
    	else{
    	 	y=n;
    	 	x=id-y;
    	}
    	vec.clear();
    	while(x<=m && y>=1){
    		vec.push_back({x, y});
    		x++;
    		y--;
    	}
    	FOR(i, 0, (int)vec.size()){
    		FOR(t, 0, 2){
    			f[i][t]=-1;
    		}
    	}
    	ans+=dp(0, 0);
    }
    
    cout << ans;
    
    return 0;
}

Compilation message (stderr)

dango_maker.cpp: In function 'int main()':
dango_maker.cpp:68:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |         freopen(".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~
dango_maker.cpp:69:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |         freopen(".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~

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