Submission #71713

#	Time	Username	Problem	Language	Result	Execution time	Memory
71713		the_general (#119)	Cross on the Grid (FXCUP3_cross)	C++98	22 / 100	4 ms	580 KiB

cross

#include<stdio.h>
#define MOD 1000000007

int a(int);
int b(int);
int c(int);
int d(int);
int n;
int A[4];
int B[4];
int C[4];
int D[4];

int a(int x){
	if(x<3) return 0;
	if(x==3) return 1;
	return (((C[1]+D[0]-B[0])%MOD+B[1])%MOD+D[0])%MOD;
}

int b(int x){
	if(x<3) return 0;
	if(x==3) return 1;
	return (((C[1]+D[0]-A[0])%MOD+A[1])%MOD+D[0])%MOD;
}

int c(int x){
	if(x<3) return 0;
	if(x==3) return 1;
	return ((A[1]+B[1])%MOD+D[0])%MOD;
}

int d(int x){
	if(x==1 || x==2){
		D[3]=1;
		for(int i=0;i<3;i++){
			D[i]=D[i+1];
		}
		return 1;
	}
	A[3]=a(x);
	B[3]=b(x);
	C[3]=c(x);
	D[3]=(((A[3]+B[3])%MOD+C[3])%MOD+D[2])%MOD;
	for(int i=0;i<3;i++){
		A[i]=A[i+1];
		B[i]=B[i+1];
		C[i]=C[i+1];
		D[i]=D[i+1];
	}
	return D[3];
}

int main(){
	scanf("%d", &n);
	for(int i=1;i<=n;i++){
		d(i);
	}
	printf("%d", D[3]);
}

Compilation message (stderr)

cross.cpp: In function 'int main()':
cross.cpp:54:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 0 / 35
• Subtask 3: 0 / 43