#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 3007;
const ll inf = 2e9;
const ll mod = 1e9 + 7;
const double pi = acos(-1);
const double eps = 1e-6;
const int dx[] = {0, -1, 0, 1}, dy[] = {1, 0, -1, 0};
const int block = 320;
ll n, k, dp[M][M][2][2], dp2[M][M][2][2];
string s, a, b;
ll solve(string x){
for(int i = 0; i <= n; ++i) for(int j = 0; j <= k; ++j) for(int Smaller : {0, 1}) for(int flip : {0, 1}) dp[i][j][Smaller][flip] = dp2[i][j][Smaller][flip] = 0;
dp[0][0][x[0] == '0'][0] = dp[0][0][x[0] == '0'][1] = 1;
dp2[0][0][x[0] == '0'][0] = dp2[0][0][x[0] == '0'][1] = 1;
for(int i = 0; i < n - 1; ++i){
for(int j = 0; j <= k; ++j){
for(int flip : {0, 1}){
ll on = (s[i + 1] - '0') ^ flip;
bool isSmaller1 = (x[i + 1] == '1' && on == 0);
bool isSmaller2 = (x[i + 1] == '1' && on);
dp[i + 1][j][1][flip] = (dp[i + 1][j][1][flip] + dp[i][j][1][flip]) % mod;
dp[i + 1][j + 1][1][!flip] = (dp[i + 1][j + 1][1][!flip] + dp[i][j][1][flip]) % mod;
dp2[i + 1][j][1][flip] = (dp2[i + 1][j][1][flip] + 2 * dp2[i][j][1][flip] + dp[i][j][1][flip] * on) % mod;
dp2[i + 1][j + 1][1][!flip] = (dp2[i + 1][j + 1][1][!flip] + 2 * dp2[i][j][1][flip] + dp[i][j][1][flip] * !on) % mod;
if(x[i + 1] == '1' || !on) dp[i + 1][j][isSmaller1][flip] = (dp[i + 1][j][isSmaller1][flip] + dp[i][j][0][flip]) % mod;
if(x[i + 1] == '1' || on) dp[i + 1][j + 1][isSmaller2][!flip] = (dp[i + 1][j + 1][isSmaller2][!flip] + dp[i][j][0][flip]) % mod;
if(x[i + 1] == '1' || !on) dp2[i + 1][j][isSmaller1][flip] = (dp2[i + 1][j][isSmaller1][flip] + 2 * dp2[i][j][0][flip] + dp[i][j][0][flip] * on) % mod;
if(x[i + 1] == '1' || on) dp2[i + 1][j + 1][isSmaller2][!flip] = (dp2[i + 1][j + 1][isSmaller2][!flip] + 2 * dp2[i][j][0][flip] + dp[i][j][0][flip] * !on) % mod;
}
}
}
ll ret = 0;
for(int i : {0, 1})
for(int j : {0, 1})
ret = (ret + dp2[n - 1][k][i][j]) % mod;
return ret;
}
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> k >> s >> a >> b;
s = '#' + s;
for(int i = 1; i < n; ++i){
if(s[i] == 'L') s[i] = '0';
else s[i] = '1';
}
for(int i = n - 1; i >= 0; --i){
if(a[i] == '0') a[i] = '1';
else{
a[i] = '0';
break;
}
}
cout << (solve(b) - solve(a) + mod) % mod;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
8660 KB |
Output is correct |
2 |
Correct |
6 ms |
8260 KB |
Output is correct |
3 |
Correct |
4 ms |
7928 KB |
Output is correct |
4 |
Correct |
4 ms |
7508 KB |
Output is correct |
5 |
Correct |
3 ms |
6996 KB |
Output is correct |
6 |
Correct |
3 ms |
6728 KB |
Output is correct |
7 |
Correct |
3 ms |
6228 KB |
Output is correct |
8 |
Correct |
3 ms |
5716 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
468 KB |
Output is correct |
2 |
Correct |
1 ms |
468 KB |
Output is correct |
3 |
Correct |
1 ms |
456 KB |
Output is correct |
4 |
Correct |
1 ms |
588 KB |
Output is correct |
5 |
Correct |
1 ms |
468 KB |
Output is correct |
6 |
Correct |
1 ms |
468 KB |
Output is correct |
7 |
Correct |
1 ms |
468 KB |
Output is correct |
8 |
Correct |
1 ms |
596 KB |
Output is correct |
9 |
Correct |
1 ms |
468 KB |
Output is correct |
10 |
Correct |
1 ms |
456 KB |
Output is correct |
11 |
Correct |
1 ms |
468 KB |
Output is correct |
12 |
Correct |
1 ms |
456 KB |
Output is correct |
13 |
Correct |
1 ms |
580 KB |
Output is correct |
14 |
Correct |
1 ms |
468 KB |
Output is correct |
15 |
Correct |
1 ms |
468 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
84 ms |
44608 KB |
Output is correct |
2 |
Correct |
65 ms |
33500 KB |
Output is correct |
3 |
Correct |
74 ms |
37044 KB |
Output is correct |
4 |
Correct |
146 ms |
67320 KB |
Output is correct |
5 |
Correct |
58 ms |
32016 KB |
Output is correct |
6 |
Correct |
151 ms |
69812 KB |
Output is correct |
7 |
Correct |
41 ms |
22868 KB |
Output is correct |
8 |
Correct |
75 ms |
36684 KB |
Output is correct |
9 |
Correct |
7 ms |
9812 KB |
Output is correct |
10 |
Correct |
64 ms |
33908 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
8660 KB |
Output is correct |
2 |
Correct |
6 ms |
8260 KB |
Output is correct |
3 |
Correct |
4 ms |
7928 KB |
Output is correct |
4 |
Correct |
4 ms |
7508 KB |
Output is correct |
5 |
Correct |
3 ms |
6996 KB |
Output is correct |
6 |
Correct |
3 ms |
6728 KB |
Output is correct |
7 |
Correct |
3 ms |
6228 KB |
Output is correct |
8 |
Correct |
3 ms |
5716 KB |
Output is correct |
9 |
Correct |
0 ms |
468 KB |
Output is correct |
10 |
Correct |
1 ms |
468 KB |
Output is correct |
11 |
Correct |
1 ms |
456 KB |
Output is correct |
12 |
Correct |
1 ms |
588 KB |
Output is correct |
13 |
Correct |
1 ms |
468 KB |
Output is correct |
14 |
Correct |
1 ms |
468 KB |
Output is correct |
15 |
Correct |
1 ms |
468 KB |
Output is correct |
16 |
Correct |
1 ms |
596 KB |
Output is correct |
17 |
Correct |
1 ms |
468 KB |
Output is correct |
18 |
Correct |
1 ms |
456 KB |
Output is correct |
19 |
Correct |
1 ms |
468 KB |
Output is correct |
20 |
Correct |
1 ms |
456 KB |
Output is correct |
21 |
Correct |
1 ms |
580 KB |
Output is correct |
22 |
Correct |
1 ms |
468 KB |
Output is correct |
23 |
Correct |
1 ms |
468 KB |
Output is correct |
24 |
Correct |
84 ms |
44608 KB |
Output is correct |
25 |
Correct |
65 ms |
33500 KB |
Output is correct |
26 |
Correct |
74 ms |
37044 KB |
Output is correct |
27 |
Correct |
146 ms |
67320 KB |
Output is correct |
28 |
Correct |
58 ms |
32016 KB |
Output is correct |
29 |
Correct |
151 ms |
69812 KB |
Output is correct |
30 |
Correct |
41 ms |
22868 KB |
Output is correct |
31 |
Correct |
75 ms |
36684 KB |
Output is correct |
32 |
Correct |
7 ms |
9812 KB |
Output is correct |
33 |
Correct |
64 ms |
33908 KB |
Output is correct |
34 |
Correct |
103 ms |
52904 KB |
Output is correct |
35 |
Correct |
44 ms |
23252 KB |
Output is correct |
36 |
Correct |
70 ms |
33276 KB |
Output is correct |
37 |
Correct |
142 ms |
64936 KB |
Output is correct |
38 |
Correct |
22 ms |
15104 KB |
Output is correct |
39 |
Correct |
117 ms |
57324 KB |
Output is correct |
40 |
Correct |
20 ms |
14036 KB |
Output is correct |
41 |
Correct |
90 ms |
40760 KB |
Output is correct |
42 |
Correct |
103 ms |
50160 KB |
Output is correct |
43 |
Correct |
101 ms |
49876 KB |
Output is correct |
44 |
Correct |
126 ms |
57016 KB |
Output is correct |
45 |
Correct |
41 ms |
21908 KB |
Output is correct |
46 |
Correct |
99 ms |
46308 KB |
Output is correct |
47 |
Correct |
96 ms |
48616 KB |
Output is correct |
48 |
Correct |
60 ms |
31136 KB |
Output is correct |
49 |
Correct |
8 ms |
9428 KB |
Output is correct |
50 |
Correct |
114 ms |
55220 KB |
Output is correct |
51 |
Correct |
56 ms |
29108 KB |
Output is correct |
52 |
Correct |
59 ms |
30948 KB |
Output is correct |
53 |
Correct |
140 ms |
65780 KB |
Output is correct |
54 |
Correct |
39 ms |
23736 KB |
Output is correct |
55 |
Correct |
107 ms |
53980 KB |
Output is correct |
56 |
Correct |
127 ms |
60512 KB |
Output is correct |
57 |
Correct |
18 ms |
13780 KB |
Output is correct |
58 |
Correct |
102 ms |
48816 KB |
Output is correct |