#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <math.h>
#include <assert.h>
#include <queue>
#include <map>
#include <set>
#include <string>
#include <algorithm>
#include <iostream>
#include <functional>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <bitset>
using namespace std;
typedef long long ll;
#define Fi first
#define Se second
#define pb(x) push_back(x)
#define szz(x) ((int)(x).size())
#define rep(i, n) for(int i=0;i<n;i++)
#define all(x) (x).begin(), (x).end()
typedef tuple<int, int, int> t3;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef long double ldouble;
const int MOD = 1e9 + 7;
const int L = 16;
struct mat {
int p[L][L];
mat operator*(mat A) {
mat res;
rep(a, L) rep(b, L) res.p[a][b] = 0;
rep(a, L) rep(c, L) rep(b, L) if(p[a][c] && A.p[c][b]) res.p[a][b] = (res.p[a][b] + p[a][c] * (ll)A.p[c][b]) % MOD;
return res;
}
};
int chk(int x) {
int a = x & 3, b = (x >> 2) & 3;
if(a && b && abs(a - b) <= 1) return 0;
return 1;
}
int main() {
mat X, R;
rep(i, L) rep(j, L) X.p[i][j] = 0;
rep(i, L) rep(j, L) if(chk(i) && chk(j) && (i & 3) == ((j >> 2) & 3) && ((j & 3) == 0 || ((i >> 2) & 3) != (j & 3))) X.p[i][j] = 1;
rep(i, L) rep(j, L) R.p[i][j] = (i == j ? 1 : 0);
int N; scanf("%d", &N); N -= 2;
while(N) {
if(N & 1) R = R * X;
X = X * X;
N >>= 1;
}
ll ans = 0;
rep(i, L) ans = (ans + R.p[0][i]) % MOD;
printf("%lld\n", ans);
return 0;
}
Compilation message
cross.cpp: In function 'int main()':
cross.cpp:56:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
int N; scanf("%d", &N); N -= 2;
~~~~~^~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
248 KB |
Output is correct |
2 |
Correct |
3 ms |
356 KB |
Output is correct |
3 |
Correct |
2 ms |
432 KB |
Output is correct |
4 |
Correct |
2 ms |
640 KB |
Output is correct |
5 |
Correct |
2 ms |
640 KB |
Output is correct |
6 |
Correct |
2 ms |
640 KB |
Output is correct |
7 |
Correct |
2 ms |
640 KB |
Output is correct |
8 |
Correct |
4 ms |
664 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
248 KB |
Output is correct |
2 |
Correct |
3 ms |
356 KB |
Output is correct |
3 |
Correct |
2 ms |
432 KB |
Output is correct |
4 |
Correct |
2 ms |
640 KB |
Output is correct |
5 |
Correct |
2 ms |
640 KB |
Output is correct |
6 |
Correct |
2 ms |
640 KB |
Output is correct |
7 |
Correct |
2 ms |
640 KB |
Output is correct |
8 |
Correct |
4 ms |
664 KB |
Output is correct |
9 |
Correct |
2 ms |
664 KB |
Output is correct |
10 |
Correct |
2 ms |
664 KB |
Output is correct |
11 |
Correct |
3 ms |
664 KB |
Output is correct |
12 |
Correct |
2 ms |
664 KB |
Output is correct |
13 |
Correct |
2 ms |
664 KB |
Output is correct |
14 |
Correct |
3 ms |
720 KB |
Output is correct |
15 |
Correct |
2 ms |
720 KB |
Output is correct |
16 |
Correct |
3 ms |
720 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
248 KB |
Output is correct |
2 |
Correct |
3 ms |
356 KB |
Output is correct |
3 |
Correct |
2 ms |
432 KB |
Output is correct |
4 |
Correct |
2 ms |
640 KB |
Output is correct |
5 |
Correct |
2 ms |
640 KB |
Output is correct |
6 |
Correct |
2 ms |
640 KB |
Output is correct |
7 |
Correct |
2 ms |
640 KB |
Output is correct |
8 |
Correct |
4 ms |
664 KB |
Output is correct |
9 |
Correct |
2 ms |
664 KB |
Output is correct |
10 |
Correct |
2 ms |
664 KB |
Output is correct |
11 |
Correct |
3 ms |
664 KB |
Output is correct |
12 |
Correct |
2 ms |
664 KB |
Output is correct |
13 |
Correct |
2 ms |
664 KB |
Output is correct |
14 |
Correct |
3 ms |
720 KB |
Output is correct |
15 |
Correct |
2 ms |
720 KB |
Output is correct |
16 |
Correct |
3 ms |
720 KB |
Output is correct |
17 |
Correct |
3 ms |
720 KB |
Output is correct |
18 |
Correct |
3 ms |
780 KB |
Output is correct |
19 |
Correct |
3 ms |
780 KB |
Output is correct |
20 |
Correct |
3 ms |
788 KB |
Output is correct |
21 |
Correct |
3 ms |
796 KB |
Output is correct |
22 |
Correct |
3 ms |
796 KB |
Output is correct |
23 |
Correct |
2 ms |
796 KB |
Output is correct |
24 |
Correct |
2 ms |
796 KB |
Output is correct |
25 |
Correct |
4 ms |
820 KB |
Output is correct |