# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
559849 | _Body | Linear Garden (IOI08_linear_garden) | Java | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
#define int long long
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r){
uniform_int_distribution<int> uid(l, r);
return uid(rng);
}
string s;
int N,M;
int dp[2][2][5][5][5];
int DP()
{
for(int i=N;i>=0;i--)
{
for(int tight=0;tight<2;tight++)
{
for(int mn=0;mn<=2;mn++)
{
for(int mx=2;mx<=4;mx++)
{
if(mx-mn>2)
continue;
for(int where=mn;where<=mx;where++)
{
if(tight)
{
int &ret=dp[i&1][1][mn][mx][where];
ret=0;
if(i==N){
ret=1;
continue;
}
for(int d=0;d<=s[i]-'0';d++)
{
if(d==s[i]-'0')
{
if(d==0&&where-1>=0)
ret+=dp[(i+1)&1][1][min(mn,where-1)][mx][where-1];
else if(d==1&&where+1<5) ret+=dp[(i+1)&1][1][mn][max(mx,where+1)][where+1];
}
else {
if(d==0&&where-1>=0)
ret+=dp[(i+1)&1][0][min(mn,where-1)][mx][where-1];
else if(d==1&&where+1<5) ret+=dp[(i+1)&1][0][mn][max(mx,where+1)][where+1];
}
ret=ret%M;
}
}
else {
int &ret=dp[i&1][0][mn][mx][where];
ret=0;
if(i==N){
ret=1;
continue;
}
for(int d=0;d<=1;d++)
{
if(d==s[i]-'0')
{
if(d==0&&where-1>=0)
ret+=dp[(i+1)&1][0][min(mn,where-1)][mx][where-1];
else if(d==1&&where+1<5) ret+=dp[(i+1)&1][0][mn][max(mx,where+1)][where+1];
}
else {
if(d==0&&where-1>=0)
ret+=dp[(i+1)&1][0][min(mn,where-1)][mx][where-1];
else if(d==1&&where+1<5)
ret+=dp[(i+1)&1][0][mn][max(mx,where+1)][where+1];
}
ret=ret%M;
}
}
}
}
}
}
}
return dp[0][1][2][2][2];
}
int32_t main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
// freopen("team.in","r",stdin);
// freopen("team.out","w",stdout);
int tt=1;
// cin>>tt;
int T=1;
while(tt--)
{
cin>>N>>M;
cin>>s;
for(int i=0;i<N;i++)
{
if(s[i]=='L')
s[i]='0';
else s[i]='1';
}
cout<<DP()<<"\n";
//cout<<s<<"\n";
}
}
/*stolen stuff you should look for
* int overflow, array bounds
* special cases (n=1?)
* do smth instead of nothing and stay organized
* WRITE STUFF DOWN
* DON'T GET STUCK ON ONE APPROACH
*/