Submission #71719

#	Time	Username	Problem	Language	Result	Execution time	Memory
71719		퍼솔 가즈아ㅏㅏㅏ (#119)	Cross on the Grid (FXCUP3_cross)	C++14	100 / 100	4 ms	900 KiB

cross

#include <cstdio>
typedef struct{
    long long M[9][9];
} mat;
mat A;
long long X[9][9]={1,0,0,0,1,0,1,1,0, 1,0,0,0,0,0,1,1,0, 1,0,0,0,1,0,0,1,0, 1,0,0,0,1,0,1,0,0, 0,1,0,0,0,0,0,0,1, 0,1,0,0,0,0,0,0,0, 0,0,1,0,0,0,0,0,0, 0,0,0,1,0,1,0,0,0, 0,0,0,1,0,0,0,0,0};
mat matmul(mat x, mat y){
    mat ret;
    for(int i=0;i<9;i++){
        for(int j=0;j<9;j++){
            ret.M[i][j]=0LL;
        }
    }
    for(int i=0;i<9;i++){
        for(int j=0;j<9;j++){
            for(int k=0;k<9;k++){
                ret.M[i][k]=(ret.M[i][k]+x.M[i][j]*y.M[j][k])%1000000007LL;
            }
        }
    }
    return ret;
}
mat matpow(mat x, int p){
    if(p==1) return x;
    mat h=matpow(x,p/2);
    if(p&1) return matmul(matmul(h,h),x);
    return matmul(h,h);
}
mat ans;
long long pans=0LL;
int main(){
    int N;
    scanf("%d",&N);
    for(int i=0;i<9;i++){
        for(int j=0;j<9;j++){
            A.M[i][j]=X[i][j];
        }
    }
    ans=matpow(A,N-2);
    for(int i=0;i<9;i++) pans=(pans+ans.M[i][0])%1000000007LL;
    printf("%lld",pans);
}

Compilation message (stderr)

cross.cpp: In function 'int main()':
cross.cpp:33:10: 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: 35 / 35
• Subtask 3: 43 / 43