#include<bits/stdc++.h> //#pragma GCC optimize("Ofast") //#pragma GCC optimize("trapv") #define st first #define nd second #define pb(x) push_back(x) #define pp(x) pop_back(x) #define mp(a, b) make_pair(a, b) #define all(x) (x).begin(), (x).end() #define rev(x) reverse(all(x)) #define sor(x) sort(all(x)) #define sz(x) (int)(x).size() #define rsz(x) resize(x) using namespace std; ///~~~~~~~~~~~~~~~~~~~~~~~~~~ void debug(){cerr<<"\n";} template <typename H, typename... T> void debug(H h, T... t) {cerr<<h; if (sizeof...(t)) cerr << ", "; debug(t...);} #define deb(x...) cerr<<#x<<" = ";debug(x); ///~~~~~~~~~~~~~~~~~~~~~~~~~ typedef long long ll; typedef long double ld; typedef pair<int, int> pii; typedef pair<ll, ll> pll; typedef vector<int> vi; typedef vector<pii > vii; typedef vector<ll> vl; typedef vector<pll> vll; typedef string str; #define BOOST ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL); mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count()); const int N=1<<19, INF=1e9+5, mod=1e9+7; int n1[N], n3[N]; int tab[N+N]; int quer(int v, int c){ v+=N; //cout<<v-N<<" "<<c<<"\n"; while(v>=1){ if((v&1)==0 && tab[v+1]>=c){ v++; while(v<N){ if(tab[2*v]>=c)v=2*v; else v=2*v+1; } return v-N; } v/=2; } assert(false); return 0; } int main(){ const ld EPS=-1e-9; BOOST; int n; ld v1, v2, v3; ld v0; cin>>n>>v0>>v1>>v2>>v3; string s[4]; cin>>s[1]>>s[2]>>s[3]; s[3][0]='.'; /*for(int i=0; i<=18; i++){ cout<<i<<"\n"; for(int j=0; j<3; j++)cout<<string(i*(2-j), '.')<<s[j+1]<<"\n"; cout<<"\n"; }*/ for(int i=0; i<3; i++)s[i].pb('.'); n1[n]=n3[n]=INF; for(int i=n-1; i>=0; i--){ if(s[3][i]=='.')n3[i]=n3[i+1]+1; else n3[i]=-1; } for(int i=0; i<=n; i++){ tab[N+i+1]=n3[i]; } for(int i=N-1; i>0; i--){ tab[i]=max(tab[2*i+1], tab[2*i]); } for(int i=n-1; i>=0; i--){ if(s[1][i]=='.')n1[i]=n1[i+1]; else n1[i]=i-1; } for(int i=0; i<n; i++){ if(s[1][i]=='#')n1[i]=n1[i-1]; } int lst[4]={-1, -1, -1, -1}; for(int i=0; i<n; i++){ for(int j=1; j<=3; j++)if(s[j][i]=='#')lst[j]=i; } ld t=0; int prv=0; for(int i=1; i<=lst[2]+1; i++){ if(s[2][i]!='.')continue; ld pos=prv+v2*t; //deb(prv, t); ld t2=t+(i-prv)/(v0-v2); int id1=n1[min(int(-EPS+pos-v1*t), n)]; ld t1=(id1-i)/(v2-v1); //deb(t1, t2, id1, pos, pos-v1*t, EPS+floor(EPS+pos-v1*t)); ld wym=(i-prv)/(v0-v2)*(v0-v3); ld pos2=pos-v3*t; int id=floor(pos2); //deb(wym, pos2, id, t1, n3[id], n3[id]+id-wym-pos2); if(id>=n || (n3[id]+id-wym-pos2>=EPS))t1=min(t1, t2); else{ id=ceil(pos2); //id++; //while((ld)n3[id]<wym)id++; id=quer(id, int(ceil(wym)-EPS))-1; //deb(id); t1=min(t1, (id-prv)/(v2-v3)+t2-t); } //deb(wym, pos2, id, t1); if(prv+1!=i)t=max(t2, t1); else t=t2; prv=i; //deb(); } //deb(t); ld pos=lst[2]+1+v2*t-v0*t; //deb(pos, lst[1], lst[3]); //deb(lst[1]+t); t=max(t, (lst[1]+1-pos)/(v0-v1)); t=max(t, (lst[3]+1-pos)/(v0-v3)); //ld ans; //cin>>ans; //assert((t-ans)<1e-10); //t=ans; //if(n>=16)t=ans; cout<<fixed<<setprecision(15)<<t<<"\n"; //for(int i=0; i<n; i++) }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 | #include<bits/stdc++.h> //#pragma GCC optimize("Ofast") //#pragma GCC optimize("trapv") #define st first #define nd second #define pb(x) push_back(x) #define pp(x) pop_back(x) #define mp(a, b) make_pair(a, b) #define all(x) (x).begin(), (x).end() #define rev(x) reverse(all(x)) #define sor(x) sort(all(x)) #define sz(x) (int)(x).size() #define rsz(x) resize(x) using namespace std; ///~~~~~~~~~~~~~~~~~~~~~~~~~~ void debug(){cerr<<"\n";} template <typename H, typename... T> void debug(H h, T... t) {cerr<<h; if (sizeof...(t)) cerr << ", "; debug(t...);} #define deb(x...) cerr<<#x<<" = ";debug(x); ///~~~~~~~~~~~~~~~~~~~~~~~~~ typedef long long ll; typedef long double ld; typedef pair<int, int> pii; typedef pair<ll, ll> pll; typedef vector<int> vi; typedef vector<pii > vii; typedef vector<ll> vl; typedef vector<pll> vll; typedef string str; #define BOOST ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL); mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count()); const int N=1<<19, INF=1e9+5, mod=1e9+7; int n1[N], n3[N]; int tab[N+N]; int quer(int v, int c){ v+=N; //cout<<v-N<<" "<<c<<"\n"; while(v>=1){ if((v&1)==0 && tab[v+1]>=c){ v++; while(v<N){ if(tab[2*v]>=c)v=2*v; else v=2*v+1; } return v-N; } v/=2; } assert(false); return 0; } int main(){ const ld EPS=-1e-9; BOOST; int n; ld v1, v2, v3; ld v0; cin>>n>>v0>>v1>>v2>>v3; string s[4]; cin>>s[1]>>s[2]>>s[3]; s[3][0]='.'; /*for(int i=0; i<=18; i++){ cout<<i<<"\n"; for(int j=0; j<3; j++)cout<<string(i*(2-j), '.')<<s[j+1]<<"\n"; cout<<"\n"; }*/ for(int i=0; i<3; i++)s[i].pb('.'); n1[n]=n3[n]=INF; for(int i=n-1; i>=0; i--){ if(s[3][i]=='.')n3[i]=n3[i+1]+1; else n3[i]=-1; } for(int i=0; i<=n; i++){ tab[N+i+1]=n3[i]; } for(int i=N-1; i>0; i--){ tab[i]=max(tab[2*i+1], tab[2*i]); } for(int i=n-1; i>=0; i--){ if(s[1][i]=='.')n1[i]=n1[i+1]; else n1[i]=i-1; } for(int i=0; i<n; i++){ if(s[1][i]=='#')n1[i]=n1[i-1]; } int lst[4]={-1, -1, -1, -1}; for(int i=0; i<n; i++){ for(int j=1; j<=3; j++)if(s[j][i]=='#')lst[j]=i; } ld t=0; int prv=0; for(int i=1; i<=lst[2]+1; i++){ if(s[2][i]!='.')continue; ld pos=prv+v2*t; //deb(prv, t); ld t2=t+(i-prv)/(v0-v2); int id1=n1[min(int(-EPS+pos-v1*t), n)]; ld t1=(id1-i)/(v2-v1); //deb(t1, t2, id1, pos, pos-v1*t, EPS+floor(EPS+pos-v1*t)); ld wym=(i-prv)/(v0-v2)*(v0-v3); ld pos2=pos-v3*t; int id=floor(pos2); //deb(wym, pos2, id, t1, n3[id], n3[id]+id-wym-pos2); if(id>=n || (n3[id]+id-wym-pos2>=EPS))t1=min(t1, t2); else{ id=ceil(pos2); //id++; //while((ld)n3[id]<wym)id++; id=quer(id, int(ceil(wym)-EPS))-1; //deb(id); t1=min(t1, (id-prv)/(v2-v3)+t2-t); } //deb(wym, pos2, id, t1); if(prv+1!=i)t=max(t2, t1); else t=t2; prv=i; //deb(); } //deb(t); ld pos=lst[2]+1+v2*t-v0*t; //deb(pos, lst[1], lst[3]); //deb(lst[1]+t); t=max(t, (lst[1]+1-pos)/(v0-v1)); t=max(t, (lst[3]+1-pos)/(v0-v3)); //ld ans; //cin>>ans; //assert((t-ans)<1e-10); //t=ans; //if(n>=16)t=ans; cout<<fixed<<setprecision(15)<<t<<"\n"; //for(int i=0; i<n; i++) } |