#include<stdio.h>
#include<stdlib.h>
#define MAXN 1005
const int MOD=1e9 + 7;
char ans[MAXN];
char A[MAXN], B[MAXN];
int two[MAXN];
long long dp[MAXN][MAXN][2][2];
bool cA[MAXN], cB[MAXN];
void add(long long* a, long long b) {
*a = (*a + b) % MOD;
}
int main() {
int N, K;
long long res;
//freopen("input.txt", "r", stdin);
scanf("%d%d", &N, &K);
scanf("%s\n%s\n%s", ans, A, B);
if (A[N] != 0 || B[N - 1] == 0) {
printf("0");
return 0;
}
if (A[N - 1] == 0) {
A[0] = '1';
for (int i = 1; i < N; i++) A[i] = '0';
}
if (B[N] != 0) for (int i = 0; i < N; i++) B[i] = '1';
//printf("%s*%s*%s", A, B, ans);
for (int i = 0; i < N - 1; i++) {
cA[i] = ((ans[i] == 'L' && A[i+1] == '0') || (ans[i] == 'R' && A[i+1] == '1'));
cB[i] = ((ans[i] == 'L' && B[i+1] == '0') || (ans[i] == 'R' && B[i+1] == '1'));
//printf("[%d %d]\n", cA[i]?1:0, cB[i]?1:0);
}
two[0] = 1;
for (int i = 1; i < N; i++) two[i] = two[i - 1] * 2 % MOD;
dp[N - 1][0][0][0] = dp[N-1][0][1][0]=1ll;
//printf("%lld\n", dp[2][0][1][0]);
//for (int i = 0; i < N; i++)
//for (int j = 0; j <= K; j++) printf("i=%d, j=%d: (%lld %lld), (%lld %lld)\n", i, j, dp[i][j][0][0], dp[i][j][0][1], dp[i][j][1][0], dp[i][j][1][1]);
for (int i = N - 2; i >= 0; i--) for(int j=0; j<=K; j++){
dp[i][j][0][0] = dp[i + 1][j][0][0];
dp[i][j][1][0] = dp[i + 1][j][1][0];
if (j > 0) {
add(&dp[i][j][0][0], dp[i + 1][j - 1][1][0]);
add(&dp[i][j][1][0], dp[i + 1][j - 1][0][0]);
}
dp[i][j][0][1] = dp[i + 1][j][0][1];
dp[i][j][1][1] = dp[i + 1][j][1][1];
if (ans[i] == 'L') add(&dp[i][j][1][1], two[N - i - 2] * dp[i + 1][j][1][0]);
else add(&dp[i][j][0][1], two[N - i - 2] * dp[i + 1][j][0][0]);
if (j > 0) {
add(&dp[i][j][0][1], dp[i + 1][j - 1][1][1]);
add(&dp[i][j][1][1], dp[i + 1][j - 1][0][1]);
if (ans[i] == 'L') add(&dp[i][j][0][1], two[N - i - 2] * dp[i + 1][j - 1][1][0]);
else add(&dp[i][j][1][1], two[N - i - 2] * dp[i + 1][j - 1][0][0]);
}
}
//for (int i = 0; i < N; i++)
//for (int j = 0; j <= K; j++) printf("i=%d, j=%d: (%lld %lld), (%lld %lld)\n", i, j, dp[i][j][0][0], dp[i][j][0][1], dp[i][j][1][0], dp[i][j][1][1]);
res = (dp[0][K][0][1] + dp[0][K][1][1] + two[N - 1] * (dp[0][K][0][0] + dp[0][K][1][0])) % MOD;
//printf("%lld\n", res);
long long sA=two[N-1], sB=two[N-1];
int KA = K, KB=K;
for (int i = 0; i < N - 1; i++) {
if (A[i + 1] == '1') {
//printf("@");
if (i>0&&cA[i - 1] == cA[i]) KA--;
//printf("(%d %lld)", KA, sA);
if (KA >= 0) res = (res - dp[i + 1][KA][cA[i] ? 1 : 0][1] - sA * dp[i + 1][KA][cA[i] ? 1 : 0][0]) % MOD;
if (KA > 0) res = (res - dp[i + 1][KA-1][cA[i] ? 1 : 0][1] - sA * dp[i + 1][KA-1][cA[i] ? 1 : 0][0]) % MOD;
if (i>0&&cA[i - 1] == cA[i]) KA++;
//printf("%lld", res);
add(&sA, two[N - i - 2]);
}
if (B[i + 1] == '0') {
//printf("$");
if (i>0&&cB[i - 1] == cB[i]) KB--;
//printf("(%d %lld)\n", KB, sB);
if (KB >= 0) res = (res - dp[i + 1][KB][cB[i] ? 1 : 0][1] - (sB+two[N-i-2]) * dp[i + 1][KB][cB[i] ? 1 : 0][0]) % MOD;
if(KB>0) res = (res - dp[i + 1][KB-1][cB[i] ? 1 : 0][1] - (sB+two[N-i-2]) * dp[i + 1][KB-1][cB[i] ? 1 : 0][0]) % MOD;
if (i>0&&cB[i - 1] == cB[i]) KB++;
//printf("%lld", res);
}
else add(&sB, two[N - i - 2]);
if (i > 0) {
if (cA[i - 1] != cA[i]) KA--;
if (cB[i - 1] != cB[i]) KB--;
}
res = (res + MOD) % MOD;
}
printf("%lld", res);
return 0;
}
Compilation message
ljetopica.cpp: In function 'int main()':
ljetopica.cpp:24:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &N, &K);
~~~~~^~~~~~~~~~~~~~~~
ljetopica.cpp:25:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%s\n%s\n%s", ans, A, B);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
4352 KB |
Output is correct |
2 |
Correct |
4 ms |
4224 KB |
Output is correct |
3 |
Correct |
4 ms |
3968 KB |
Output is correct |
4 |
Correct |
4 ms |
3840 KB |
Output is correct |
5 |
Correct |
4 ms |
3584 KB |
Output is correct |
6 |
Correct |
4 ms |
3328 KB |
Output is correct |
7 |
Correct |
4 ms |
3200 KB |
Output is correct |
8 |
Correct |
4 ms |
2944 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
384 KB |
Output is correct |
2 |
Correct |
2 ms |
384 KB |
Output is correct |
3 |
Correct |
2 ms |
384 KB |
Output is correct |
4 |
Correct |
2 ms |
384 KB |
Output is correct |
5 |
Correct |
2 ms |
384 KB |
Output is correct |
6 |
Correct |
2 ms |
384 KB |
Output is correct |
7 |
Correct |
2 ms |
384 KB |
Output is correct |
8 |
Correct |
2 ms |
512 KB |
Output is correct |
9 |
Correct |
2 ms |
384 KB |
Output is correct |
10 |
Correct |
2 ms |
384 KB |
Output is correct |
11 |
Correct |
2 ms |
384 KB |
Output is correct |
12 |
Correct |
2 ms |
384 KB |
Output is correct |
13 |
Correct |
2 ms |
384 KB |
Output is correct |
14 |
Correct |
2 ms |
384 KB |
Output is correct |
15 |
Correct |
2 ms |
384 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
24 ms |
22272 KB |
Output is correct |
2 |
Correct |
18 ms |
16768 KB |
Output is correct |
3 |
Correct |
18 ms |
18560 KB |
Output is correct |
4 |
Correct |
31 ms |
31736 KB |
Output is correct |
5 |
Correct |
16 ms |
16000 KB |
Output is correct |
6 |
Correct |
33 ms |
31736 KB |
Output is correct |
7 |
Correct |
14 ms |
11520 KB |
Output is correct |
8 |
Correct |
22 ms |
18296 KB |
Output is correct |
9 |
Correct |
5 ms |
4992 KB |
Output is correct |
10 |
Correct |
17 ms |
16996 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
4352 KB |
Output is correct |
2 |
Correct |
4 ms |
4224 KB |
Output is correct |
3 |
Correct |
4 ms |
3968 KB |
Output is correct |
4 |
Correct |
4 ms |
3840 KB |
Output is correct |
5 |
Correct |
4 ms |
3584 KB |
Output is correct |
6 |
Correct |
4 ms |
3328 KB |
Output is correct |
7 |
Correct |
4 ms |
3200 KB |
Output is correct |
8 |
Correct |
4 ms |
2944 KB |
Output is correct |
9 |
Correct |
2 ms |
384 KB |
Output is correct |
10 |
Correct |
2 ms |
384 KB |
Output is correct |
11 |
Correct |
2 ms |
384 KB |
Output is correct |
12 |
Correct |
2 ms |
384 KB |
Output is correct |
13 |
Correct |
2 ms |
384 KB |
Output is correct |
14 |
Correct |
2 ms |
384 KB |
Output is correct |
15 |
Correct |
2 ms |
384 KB |
Output is correct |
16 |
Correct |
2 ms |
512 KB |
Output is correct |
17 |
Correct |
2 ms |
384 KB |
Output is correct |
18 |
Correct |
2 ms |
384 KB |
Output is correct |
19 |
Correct |
2 ms |
384 KB |
Output is correct |
20 |
Correct |
2 ms |
384 KB |
Output is correct |
21 |
Correct |
2 ms |
384 KB |
Output is correct |
22 |
Correct |
2 ms |
384 KB |
Output is correct |
23 |
Correct |
2 ms |
384 KB |
Output is correct |
24 |
Correct |
24 ms |
22272 KB |
Output is correct |
25 |
Correct |
18 ms |
16768 KB |
Output is correct |
26 |
Correct |
18 ms |
18560 KB |
Output is correct |
27 |
Correct |
31 ms |
31736 KB |
Output is correct |
28 |
Correct |
16 ms |
16000 KB |
Output is correct |
29 |
Correct |
33 ms |
31736 KB |
Output is correct |
30 |
Correct |
14 ms |
11520 KB |
Output is correct |
31 |
Correct |
22 ms |
18296 KB |
Output is correct |
32 |
Correct |
5 ms |
4992 KB |
Output is correct |
33 |
Correct |
17 ms |
16996 KB |
Output is correct |
34 |
Correct |
27 ms |
26360 KB |
Output is correct |
35 |
Correct |
12 ms |
11648 KB |
Output is correct |
36 |
Correct |
16 ms |
16640 KB |
Output is correct |
37 |
Correct |
30 ms |
30200 KB |
Output is correct |
38 |
Correct |
9 ms |
7552 KB |
Output is correct |
39 |
Correct |
29 ms |
28672 KB |
Output is correct |
40 |
Correct |
7 ms |
7040 KB |
Output is correct |
41 |
Correct |
20 ms |
20352 KB |
Output is correct |
42 |
Correct |
24 ms |
25080 KB |
Output is correct |
43 |
Correct |
26 ms |
24832 KB |
Output is correct |
44 |
Correct |
27 ms |
28544 KB |
Output is correct |
45 |
Correct |
11 ms |
11008 KB |
Output is correct |
46 |
Correct |
23 ms |
23040 KB |
Output is correct |
47 |
Correct |
25 ms |
24180 KB |
Output is correct |
48 |
Correct |
16 ms |
15616 KB |
Output is correct |
49 |
Correct |
5 ms |
4736 KB |
Output is correct |
50 |
Correct |
29 ms |
27512 KB |
Output is correct |
51 |
Correct |
15 ms |
14592 KB |
Output is correct |
52 |
Correct |
15 ms |
15352 KB |
Output is correct |
53 |
Correct |
31 ms |
31736 KB |
Output is correct |
54 |
Correct |
13 ms |
11904 KB |
Output is correct |
55 |
Correct |
29 ms |
27008 KB |
Output is correct |
56 |
Correct |
32 ms |
30200 KB |
Output is correct |
57 |
Correct |
8 ms |
6912 KB |
Output is correct |
58 |
Correct |
26 ms |
24312 KB |
Output is correct |