#include <bits/stdc++.h>
using namespace std;
typedef long long llint;
const int maxn = 1010;
const llint mod = 1e9+7;
int n, k;
char niz[maxn];
char a[maxn];
char b[maxn];
llint pot[maxn];
char tren[maxn];
llint dp[maxn][maxn][2][2][2];
pair<llint, llint> f(int x, int k, bool rev, bool flag) {
if (k < 0) return make_pair(0, 0);
if (x == n) return make_pair(0, (k == 0));
llint &ret1 = dp[x][k][rev][flag][0];
llint &ret2 = dp[x][k][rev][flag][1];
if (ret1 != -1) return make_pair(ret1, ret2);
pair<int, int> tren;
ret1 = ret2 = 0;
if (rev) {
if (niz[x - 1] == 'R') {
if (::tren[x] == '0' && flag) tren = f(x + 1, k, true, true);
else tren = f(x + 1, k, true, false);
ret1 += tren.first, ret1 %= mod;
ret2 += tren.second, ret2 %= mod;
//printf("lef (%d %d %d %d): %d %d\n", x, k, rev, flag, tren.first, tren.second);
if (::tren[x] == '0' && flag) tren = make_pair(0, 0);
else if (::tren[x] == '1' && flag) tren = f(x + 1, k - 1, false, true);
else if (!flag) tren = f(x + 1, k - 1, false, false);
ret1 += tren.first, ret1 %= mod;
ret2 += tren.second, ret2 %= mod;
ret1 += tren.second * pot[n - x - 1], ret1 %= mod;
//printf("rig (%d %d %d %d): %d %d\n", x, k, rev, flag, tren.first, tren.second);
} else {
if (::tren[x] == '0' && flag) tren = make_pair(0, 0);
else if (::tren[x] == '1' && flag) tren = f(x + 1, k, true, true);
else if (!flag) tren = f(x + 1, k, true, false);
ret1 += tren.first, ret1 %= mod;
ret2 += tren.second, ret2 %= mod;
ret1 += tren.second * pot[n - x - 1], ret1 %= mod;
//printf("rig (%d %d %d %d): %d %d\n", x, k, rev, flag, tren.first, tren.second);
if (::tren[x] == '0' && flag) tren = f(x + 1, k - 1, false, true);
else tren = f(x + 1, k - 1, false, false);
ret1 += tren.first, ret1 %= mod;
ret2 += tren.second, ret2 %= mod;
//printf("lef (%d %d %d %d): %d %d\n", x, k, rev, flag, tren.first, tren.second);
}
} else {
if (niz[x - 1] == 'L') {
if (::tren[x] == '0' && flag) tren = f(x + 1, k, false, true);
else tren = f(x + 1, k, false, false);
ret1 += tren.first, ret1 %= mod;
ret2 += tren.second, ret2 %= mod;
if (::tren[x] == '0' && flag) tren = make_pair(0, 0);
else if (::tren[x] == '1' && flag) tren = f(x + 1, k - 1, true, true);
else if (!flag) tren = f(x + 1, k - 1, true, false);
ret1 += tren.first, ret1 %= mod;
ret2 += tren.second, ret2 %= mod;
ret1 += tren.second * pot[n - x - 1], ret1 %= mod;
} else {
if (::tren[x] == '0' && flag) tren = make_pair(0, 0);
else if (::tren[x] == '1' && flag) tren = f(x + 1, k, false, true);
else if (!flag) tren = f(x + 1, k, false, false);
ret1 += tren.first, ret1 %= mod;
ret2 += tren.second, ret2 %= mod;
ret1 += tren.second * pot[n - x - 1], ret1 %= mod;
if (::tren[x] == '0' && flag) tren = f(x + 1, k - 1, true, true);
else tren = f(x + 1, k - 1, true, false);
ret1 += tren.first, ret1 %= mod;
ret2 += tren.second, ret2 %= mod;
}
}
return make_pair(ret1, ret2);
}
int main() {
scanf("%d%d", &n, &k);
scanf("%s%s%s", niz, a, b);
pot[0] = 1;
for (int i = 1; i < maxn; i++)
pot[i] = pot[i - 1] * 2, pot[i] %= mod;
bool flag = false;
for (int i = 1; i < n; i++)
if (a[i] == '1') flag = true;
llint sola = 0;
if (flag) {
for (int i = n - 1; i > 0; i--) {
if (a[i] == '1') {
a[i] = '0';
break;
} else a[i] = '1';
}
for (int i = 0; i < n; i++)
tren[i] = a[i];
memset(dp, -1, sizeof dp);
//printf("a: (%lld %lld) (%lld %lld)\n", f(1, k, false, true).first, f(1, k, false, true).second, f(1, k, true, true).first, f(1, k, true, true).second);
sola = f(1, k, false, true).first + f(1, k, true, true).first + pot[n - 1] * (f(1, k, false, true).second + f(1, k, true, true).second);
sola %= mod;
}
for (int i = 0; i < n; i++)
tren[i] = b[i];
memset(dp, -1, sizeof dp);
//printf("b: (%lld %lld) (%lld %lld)\n", f(1, k, false, true).first, f(1, k, false, true).second, f(1, k, true, true).first, f(1, k, true, true).second);
llint solb = f(1, k, false, true).first + f(1, k, true, true).first + pot[n - 1] * (f(1, k, false, true).second + f(1, k, true, true).second);
solb %= mod;
//printf("debug: %lld %lld\n", sola, solb);
printf("%lld\n", (solb + mod - sola) % mod);
return 0;
}
Compilation message
ljetopica.cpp: In function 'int main()':
ljetopica.cpp:88:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &n, &k);
~~~~~^~~~~~~~~~~~~~~~
ljetopica.cpp:89:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%s%s%s", niz, a, b);
~~~~~^~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
47 ms |
64380 KB |
Output is correct |
2 |
Correct |
46 ms |
64248 KB |
Output is correct |
3 |
Correct |
44 ms |
64248 KB |
Output is correct |
4 |
Correct |
46 ms |
64248 KB |
Output is correct |
5 |
Correct |
45 ms |
64256 KB |
Output is correct |
6 |
Correct |
46 ms |
64248 KB |
Output is correct |
7 |
Correct |
47 ms |
64248 KB |
Output is correct |
8 |
Correct |
55 ms |
64248 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
45 ms |
64248 KB |
Output is correct |
2 |
Correct |
46 ms |
64248 KB |
Output is correct |
3 |
Correct |
46 ms |
64256 KB |
Output is correct |
4 |
Correct |
46 ms |
64248 KB |
Output is correct |
5 |
Correct |
47 ms |
64248 KB |
Output is correct |
6 |
Correct |
46 ms |
64248 KB |
Output is correct |
7 |
Correct |
47 ms |
64248 KB |
Output is correct |
8 |
Correct |
49 ms |
64256 KB |
Output is correct |
9 |
Correct |
45 ms |
64248 KB |
Output is correct |
10 |
Correct |
45 ms |
64248 KB |
Output is correct |
11 |
Correct |
46 ms |
64256 KB |
Output is correct |
12 |
Correct |
47 ms |
64248 KB |
Output is correct |
13 |
Correct |
46 ms |
64376 KB |
Output is correct |
14 |
Correct |
46 ms |
64248 KB |
Output is correct |
15 |
Correct |
45 ms |
64248 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
101 ms |
64256 KB |
Output is correct |
2 |
Correct |
87 ms |
64248 KB |
Output is correct |
3 |
Correct |
96 ms |
64328 KB |
Output is correct |
4 |
Correct |
164 ms |
64256 KB |
Output is correct |
5 |
Correct |
92 ms |
64376 KB |
Output is correct |
6 |
Correct |
212 ms |
64256 KB |
Output is correct |
7 |
Correct |
86 ms |
64332 KB |
Output is correct |
8 |
Correct |
100 ms |
64256 KB |
Output is correct |
9 |
Correct |
57 ms |
64248 KB |
Output is correct |
10 |
Correct |
94 ms |
64248 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
47 ms |
64380 KB |
Output is correct |
2 |
Correct |
46 ms |
64248 KB |
Output is correct |
3 |
Correct |
44 ms |
64248 KB |
Output is correct |
4 |
Correct |
46 ms |
64248 KB |
Output is correct |
5 |
Correct |
45 ms |
64256 KB |
Output is correct |
6 |
Correct |
46 ms |
64248 KB |
Output is correct |
7 |
Correct |
47 ms |
64248 KB |
Output is correct |
8 |
Correct |
55 ms |
64248 KB |
Output is correct |
9 |
Correct |
45 ms |
64248 KB |
Output is correct |
10 |
Correct |
46 ms |
64248 KB |
Output is correct |
11 |
Correct |
46 ms |
64256 KB |
Output is correct |
12 |
Correct |
46 ms |
64248 KB |
Output is correct |
13 |
Correct |
47 ms |
64248 KB |
Output is correct |
14 |
Correct |
46 ms |
64248 KB |
Output is correct |
15 |
Correct |
47 ms |
64248 KB |
Output is correct |
16 |
Correct |
49 ms |
64256 KB |
Output is correct |
17 |
Correct |
45 ms |
64248 KB |
Output is correct |
18 |
Correct |
45 ms |
64248 KB |
Output is correct |
19 |
Correct |
46 ms |
64256 KB |
Output is correct |
20 |
Correct |
47 ms |
64248 KB |
Output is correct |
21 |
Correct |
46 ms |
64376 KB |
Output is correct |
22 |
Correct |
46 ms |
64248 KB |
Output is correct |
23 |
Correct |
45 ms |
64248 KB |
Output is correct |
24 |
Correct |
101 ms |
64256 KB |
Output is correct |
25 |
Correct |
87 ms |
64248 KB |
Output is correct |
26 |
Correct |
96 ms |
64328 KB |
Output is correct |
27 |
Correct |
164 ms |
64256 KB |
Output is correct |
28 |
Correct |
92 ms |
64376 KB |
Output is correct |
29 |
Correct |
212 ms |
64256 KB |
Output is correct |
30 |
Correct |
86 ms |
64332 KB |
Output is correct |
31 |
Correct |
100 ms |
64256 KB |
Output is correct |
32 |
Correct |
57 ms |
64248 KB |
Output is correct |
33 |
Correct |
94 ms |
64248 KB |
Output is correct |
34 |
Correct |
177 ms |
64224 KB |
Output is correct |
35 |
Correct |
127 ms |
64352 KB |
Output is correct |
36 |
Correct |
140 ms |
64320 KB |
Output is correct |
37 |
Correct |
171 ms |
64256 KB |
Output is correct |
38 |
Correct |
86 ms |
64324 KB |
Output is correct |
39 |
Correct |
176 ms |
64256 KB |
Output is correct |
40 |
Correct |
80 ms |
64276 KB |
Output is correct |
41 |
Correct |
165 ms |
64248 KB |
Output is correct |
42 |
Correct |
188 ms |
64248 KB |
Output is correct |
43 |
Correct |
165 ms |
64328 KB |
Output is correct |
44 |
Correct |
177 ms |
64348 KB |
Output is correct |
45 |
Correct |
103 ms |
64248 KB |
Output is correct |
46 |
Correct |
150 ms |
64232 KB |
Output is correct |
47 |
Correct |
163 ms |
64248 KB |
Output is correct |
48 |
Correct |
142 ms |
64324 KB |
Output is correct |
49 |
Correct |
52 ms |
64332 KB |
Output is correct |
50 |
Correct |
180 ms |
64248 KB |
Output is correct |
51 |
Correct |
128 ms |
64328 KB |
Output is correct |
52 |
Correct |
140 ms |
64328 KB |
Output is correct |
53 |
Correct |
205 ms |
64360 KB |
Output is correct |
54 |
Correct |
121 ms |
64328 KB |
Output is correct |
55 |
Correct |
201 ms |
64268 KB |
Output is correct |
56 |
Correct |
191 ms |
64248 KB |
Output is correct |
57 |
Correct |
82 ms |
64392 KB |
Output is correct |
58 |
Correct |
176 ms |
64224 KB |
Output is correct |