#include <bits/stdc++.h>
using namespace std;
const int M = int(1e9) + 7;
struct Mat{
int a[9][9];
Mat operator*(const Mat &o) const {
Mat r;
for(int i = 0; i < 9; i++){
for(int j = 0; j < 9; j++){
r.a[i][j] = 0;
for(int k = 0; k < 9; k++)
r.a[i][j] = (r.a[i][j] + 1LL * a[i][k] * o.a[k][j]) % M;
}
}
return r;
}
} a;
Mat p(Mat x, int k){
if(k == 1) return x;
if(k & 1) return p(x * x, k / 2) * x;
return p(x * x, k / 2);
}
int n, r;
int t[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}
};
int main(){
scanf("%d", &n);
if(n == 3){ puts("4"); return 0; }
for(int i = 0; i < 9; i++) for(int j = 0; j < 9; j++) a.a[i][j] = t[i][j];
a = p(a, n - 3);
for(int i = 0; i < 9; i++) for(int j = 0; j < 4; j++) r = (r + a.a[i][j]) % M;
printf("%d\n", r);
}
Compilation message
cross.cpp: In function 'int main()':
cross.cpp:41:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &n);
~~~~~^~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
380 KB |
Output is correct |
2 |
Correct |
3 ms |
380 KB |
Output is correct |
3 |
Correct |
3 ms |
380 KB |
Output is correct |
4 |
Correct |
2 ms |
412 KB |
Output is correct |
5 |
Correct |
2 ms |
488 KB |
Output is correct |
6 |
Correct |
2 ms |
488 KB |
Output is correct |
7 |
Correct |
2 ms |
488 KB |
Output is correct |
8 |
Correct |
2 ms |
564 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
380 KB |
Output is correct |
2 |
Correct |
3 ms |
380 KB |
Output is correct |
3 |
Correct |
3 ms |
380 KB |
Output is correct |
4 |
Correct |
2 ms |
412 KB |
Output is correct |
5 |
Correct |
2 ms |
488 KB |
Output is correct |
6 |
Correct |
2 ms |
488 KB |
Output is correct |
7 |
Correct |
2 ms |
488 KB |
Output is correct |
8 |
Correct |
2 ms |
564 KB |
Output is correct |
9 |
Correct |
3 ms |
564 KB |
Output is correct |
10 |
Correct |
2 ms |
564 KB |
Output is correct |
11 |
Correct |
3 ms |
564 KB |
Output is correct |
12 |
Correct |
2 ms |
564 KB |
Output is correct |
13 |
Correct |
2 ms |
564 KB |
Output is correct |
14 |
Correct |
2 ms |
596 KB |
Output is correct |
15 |
Correct |
2 ms |
596 KB |
Output is correct |
16 |
Correct |
3 ms |
596 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
380 KB |
Output is correct |
2 |
Correct |
3 ms |
380 KB |
Output is correct |
3 |
Correct |
3 ms |
380 KB |
Output is correct |
4 |
Correct |
2 ms |
412 KB |
Output is correct |
5 |
Correct |
2 ms |
488 KB |
Output is correct |
6 |
Correct |
2 ms |
488 KB |
Output is correct |
7 |
Correct |
2 ms |
488 KB |
Output is correct |
8 |
Correct |
2 ms |
564 KB |
Output is correct |
9 |
Correct |
3 ms |
564 KB |
Output is correct |
10 |
Correct |
2 ms |
564 KB |
Output is correct |
11 |
Correct |
3 ms |
564 KB |
Output is correct |
12 |
Correct |
2 ms |
564 KB |
Output is correct |
13 |
Correct |
2 ms |
564 KB |
Output is correct |
14 |
Correct |
2 ms |
596 KB |
Output is correct |
15 |
Correct |
2 ms |
596 KB |
Output is correct |
16 |
Correct |
3 ms |
596 KB |
Output is correct |
17 |
Correct |
2 ms |
724 KB |
Output is correct |
18 |
Correct |
2 ms |
724 KB |
Output is correct |
19 |
Correct |
2 ms |
724 KB |
Output is correct |
20 |
Correct |
2 ms |
724 KB |
Output is correct |
21 |
Correct |
3 ms |
724 KB |
Output is correct |
22 |
Correct |
3 ms |
724 KB |
Output is correct |
23 |
Correct |
2 ms |
724 KB |
Output is correct |
24 |
Correct |
2 ms |
724 KB |
Output is correct |
25 |
Correct |
2 ms |
724 KB |
Output is correct |