#include <stdio.h>
#include <string.h>
#define N 1000
#define MD 1000000007
int pp2[N + 1], vv[N + 1], ff[N + 1], gg[N + 1];
void init() {
int i;
pp2[0] = 1;
for (i = 1; i <= N; i++)
pp2[i] = pp2[i - 1] * 2 % MD;
ff[0] = gg[0] = 1;
for (i = 1; i <= N; i++) {
vv[i] = i == 1 ? 1 : (long long) vv[i - MD % i] * (MD / i + 1) % MD;
ff[i] = (long long) ff[i - 1] * i % MD;
gg[i] = (long long) gg[i - 1] * vv[i] % MD;
}
}
int choose(int n, int k) {
return (long long) ff[n] * gg[k] % MD * gg[n - k] % MD;
}
int main() {
static char cc[N + 1], aa[N + 1], bb[N + 1];
int n, k, i, x;
init();
scanf("%d%d%s%s%s", &n, &k, cc, aa, bb);
if (k == 0 && strcmp(aa, bb) == 0) {
x = 0;
for (i = 0; i < n; i++)
x = (x * 2 + aa[i] - '0') % MD;
printf("%d\n", x);
return 0;
}
printf("%lld\n", (long long) (pp2[n - 1] + pp2[n] - 1) % MD * choose(n - 1, k) % MD);
return 0;
}
Compilation message
ljetopica.c: In function 'main':
ljetopica.c:32:2: warning: ignoring return value of 'scanf' declared with attribute 'warn_unused_result' [-Wunused-result]
32 | scanf("%d%d%s%s%s", &n, &k, cc, aa, bb);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Correct |
0 ms |
204 KB |
Output is correct |
3 |
Correct |
0 ms |
292 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Correct |
0 ms |
204 KB |
Output is correct |
6 |
Correct |
0 ms |
204 KB |
Output is correct |
7 |
Correct |
0 ms |
204 KB |
Output is correct |
8 |
Correct |
0 ms |
204 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Correct |
0 ms |
204 KB |
Output is correct |
3 |
Correct |
0 ms |
204 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Correct |
0 ms |
204 KB |
Output is correct |
6 |
Correct |
0 ms |
204 KB |
Output is correct |
7 |
Correct |
0 ms |
204 KB |
Output is correct |
8 |
Correct |
0 ms |
204 KB |
Output is correct |
9 |
Correct |
0 ms |
204 KB |
Output is correct |
10 |
Correct |
0 ms |
204 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Correct |
0 ms |
204 KB |
Output is correct |
3 |
Correct |
0 ms |
292 KB |
Output is correct |
4 |
Correct |
0 ms |
204 KB |
Output is correct |
5 |
Correct |
0 ms |
204 KB |
Output is correct |
6 |
Correct |
0 ms |
204 KB |
Output is correct |
7 |
Correct |
0 ms |
204 KB |
Output is correct |
8 |
Correct |
0 ms |
204 KB |
Output is correct |
9 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |