#include <bits/stdc++.h>
using namespace std;
const int mod = (int)1e9 + 7;
int n, k;
string s;
int dp[1004][1004][2][2];
int sol(string f, int mst){
f = f.substr(1);
memset(dp, 0, sizeof(dp));
dp[0][0][0][0] = dp[0][0][1][0] = 1;
for(int i = 0; i < n; ++i){
for(int j = 0; j <= k; ++j){
for(int x = 0; x < 2; ++x){
for(int y = 0; y < 2; ++y){
if(!dp[i][j][x][y]) continue;
int num = ((s[i] == 'R') ^ x);
if(!num){
dp[i + 1][j][x][y | (num < f[i] - '0')] = (dp[i + 1][j][x][y | (num < f[i] - '0')] + (dp[i][j][x][y] << 1)) % mod;
if((y || f[i] - '0' == 1) && j + 1 <= k){
dp[i + 1][j + 1][x ^ 1][y] = (dp[i + 1][j + 1][x ^ 1][y] + ((dp[i][j][x][y] << 1) | 1)) % mod;
}
}
else{
if(y || f[i] - '0' == 1){
dp[i + 1][j][x][y] = (dp[i + 1][j][x][y] + ((dp[i][j][x][y] << 1) | 1)) % mod;
}
if(j + 1 <= k){
dp[i + 1][j + 1][x ^ 1][y | (0 < f[i] - '0')] = (dp[i + 1][j + 1][x ^ 1][y | (0 < f[i] - '0')] + (dp[i][j][x][y] << 1)) % mod;
}
}
}
}
}
}
if(mst){
return (dp[n][k][0][1] + dp[n][k][1][1]) % mod;
}
return (dp[n][k][0][1] + dp[n][k][1][1] + dp[n][k][0][0] + dp[n][k][1][0]) % mod;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n >> k; --n;
cin >> s;
string a, b; cin >> a >> b;
cout << (sol(b, 0) - sol(a, 1) + mod + (n >= 3)) % mod;
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
9 ms |
16084 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
8 ms |
16104 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
22 ms |
16020 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
9 ms |
16084 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |