Submission #829045

#	Time	Username	Problem	Language	Result	Execution time	Memory
829045		1075508020060209tc	Necklace (Subtask 1-3) (BOI19_necklace1)	C++14	5 / 85	21 ms	1688 KiB

necklace

#pragma GCC optimize("Ofast, no-stack-protector, unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mod=998244353;
int LN=19;
int n;int m;
int ar[6010];int br[6010];int rb[6010];
void init(){
string s;
cin>>s;
n=s.size();
s="*"+s;
for(int i=1;i<=n;i++){
    ar[i]=s[i]-'a'+1;
   // ar[i+n]=ar[i];
}
cin>>s;
m=s.size();
s="*"+s;
for(int i=1;i<=m;i++){
    br[i]=s[i]-'a'+1;
    //br[i+m]=br[i];
}
for(int i=1;i<=m;i++){
    rb[i]=br[i];
}
reverse(rb+1,rb+m+1);
}
int psa[20][6010];int psb[20][6010];
int pssa[20][6010];int pssb[20][6010];
int pxa[20][6010];int pxb[20][6010];
int psrb[20][6010];
int pssrb[20][6010];
int pxrb[20][6010];
void precalc(int len){
    for(int i=1;i+len-1<=n;i++){
        int v=ar[i];
        for(int j=2;j<=len;j++){
            v=v*10+ar[i+j-1];
        }
        psa[len][i]=(psa[len][i-1]+v)%mod;
        pssa[len][i]=(pssa[len][i-1]+v*v)%mod;
        pxa[len][i]=pxa[len][i-1]^v;
    }
    for(int i=1;i+len-1<=m;i++){
        int v=br[i];
        for(int j=2;j<=len;j++){
            v=v*10+br[i+j-1];
        }
        psb[len][i]=(psb[len][i-1]+v)%mod;
        pssb[len][i]=(pssb[len][i-1]+v*v)%mod;
        pxb[len][i]=pxb[len][i-1]^v;
    }
    for(int i=1;i+len-1<=m;i++){
        int v=rb[i];
        for(int j=2;j<=len;j++){
            v=v*10+rb[i+j-1];
        }
        psrb[len][i]=(psrb[len][i-1]+v)%mod;
        pssrb[len][i]=(pssrb[len][i-1]+v*v)%mod;
        pxrb[len][i]=pxrb[len][i-1]^v;
    }
}

int cyc(int l,int r,int st,int len){
    int ret=ar[st];
    for(int i=2;i<=len;i++){
        st++;
        if(st==r+1){st=l;}
        ret=ret*10+ar[st];
    }
    return ret;
}
int cycb(int l,int r,int st,int len){
    int ret=br[st];
    for(int i=2;i<=len;i++){
        st++;
        if(st==r+1){st=l;}
        ret=ret*10+br[st];
    }
    return ret;
}
int cycrb(int l,int r,int st,int len){
    int ret=rb[st];
    for(int i=2;i<=len;i++){
        st++;
        if(st==r+1){st=l;}
        ret=ret*10+rb[st];
    }
    return ret;
}

int ansa;int ansb;
int ok(int mi){
map<vector<array<int,3>>,int>mp;
for(int i=1;i<=n-mi+1;i++){
    vector<array<int,3>>vc;
    int l=i;int r=i+mi-1;
    for(int len=1;len<=LN;len++){
        array<int,3>tar;
        tar[0]=0;tar[1]=0;tar[2]=0;
        if(r-len+1>=l){
            tar[0]=(psa[len][r-len+1]-psa[len][l-1]+mod)%mod;
            tar[1]=(pssa[len][r-len+1]-pssa[len][l-1]+mod)%mod;
            tar[2]=pxa[len][r-len+1]^pxa[len][l-1];
        }
        for(int j=max(l,r-len+1+1);j<=r;j++){
            int v=cyc(l,r,j,len);
            tar[0]=(tar[0]+v)%mod;
            tar[1]=(tar[1]+v*v)%mod;
            tar[2]=tar[2]^v;
        }
      //  cout<<i<<" "<<tar[0]<<" "<<tar[1]<<" "<<tar[2]<<endl;
        vc.push_back(tar);
    }
    mp[vc]=i;
}
for(int i=1;i<=m-mi+1;i++){
    vector<array<int,3>>vc;
    int l=i;int r=i+mi-1;
    for(int len=1;len<=LN;len++){
        array<int,3>tar;
        tar[0]=0;tar[1]=0;tar[2]=0;
        if(r-len+1>=l){
            tar[0]=(psb[len][r-len+1]-psb[len][l-1]+mod)%mod;
            tar[1]=(pssb[len][r-len+1]-pssb[len][l-1]+mod)%mod;
            tar[2]=pxb[len][r-len+1]^pxb[len][l-1];
        }
        for(int j=max(l,r-len+1+1);j<=r;j++){
            int v=cycb(l,r,j,len);
            tar[0]=(tar[0]+v)%mod;
            tar[1]=(tar[1]+v*v)%mod;
            tar[2]=tar[2]^v;
        }
        vc.push_back(tar);
    }
    if(mp[vc]>=1){
        ansa=mp[vc];
        ansb=i;
        return 1;
    }
}
for(int i=1;i<=m-mi+1;i++){
    vector<array<int,3>>vc;
    int l=i;int r=i+mi-1;
    for(int len=1;len<=LN;len++){
        array<int,3>tar;
        tar[0]=0;tar[1]=0;tar[2]=0;
        if(r-len+1>=l){
            tar[0]=(psrb[len][r-len+1]-psrb[len][l-1]+mod)%mod;
            tar[1]=(pssrb[len][r-len+1]-pssrb[len][l-1]+mod)%mod;
            tar[2]=pxrb[len][r-len+1]^pxrb[len][l-1];
        }
        for(int j=max(l,r-len+1+1);j<=r;j++){
            int v=cycrb(l,r,j,len);
            tar[0]=(tar[0]+v)%mod;
            tar[1]=(tar[1]+v*v)%mod;
            tar[2]=tar[2]^v;
        }
        vc.push_back(tar);
    }
    if(mp[vc]>=1){
        ansa=mp[vc];
        ansb=m-(i+mi-1)+1;
        return 1;
    }
}
return 0;
}

signed main()
{
    init();
    for(int i=1;i<=LN;i++){
        precalc(i);
    }/*
    for(int i=1;i<=n;i++){
        cout<<ar[i]<<" ";
    }cout<<endl;
*/
  //  ok(1);return 0;

    int l=0;int r=n;
    while(l<r){
        int mi=l+(r-l+1)/2;
        if(mi==0||ok(mi)){
            l=mi;
        }else{
            r=mi-1;
        }
    }
    cout<<l<<endl;
    ok(l);
    cout<<ansa-1<<" "<<ansb-1<<endl;

}

Compilation message (stderr)

necklace.cpp:1:63: warning: bad option '-f no-stack-protector' to pragma 'optimize' [-Wpragmas]
    1 | #pragma GCC optimize("Ofast, no-stack-protector, unroll-loops")
      |                                                               ^
necklace.cpp:1:63: warning: bad option '-f unroll-loops' to pragma 'optimize' [-Wpragmas]
necklace.cpp:9:11: warning: bad option '-f no-stack-protector' to attribute 'optimize' [-Wattributes]
    9 | void init(){
      |           ^
necklace.cpp:9:11: warning: bad option '-f unroll-loops' to attribute 'optimize' [-Wattributes]
necklace.cpp:36:21: warning: bad option '-f no-stack-protector' to attribute 'optimize' [-Wattributes]
   36 | void precalc(int len){
      |                     ^
necklace.cpp:36:21: warning: bad option '-f unroll-loops' to attribute 'optimize' [-Wattributes]
necklace.cpp:66:35: warning: bad option '-f no-stack-protector' to attribute 'optimize' [-Wattributes]
   66 | int cyc(int l,int r,int st,int len){
      |                                   ^
necklace.cpp:66:35: warning: bad option '-f unroll-loops' to attribute 'optimize' [-Wattributes]
necklace.cpp:75:36: warning: bad option '-f no-stack-protector' to attribute 'optimize' [-Wattributes]
   75 | int cycb(int l,int r,int st,int len){
      |                                    ^
necklace.cpp:75:36: warning: bad option '-f unroll-loops' to attribute 'optimize' [-Wattributes]
necklace.cpp:84:37: warning: bad option '-f no-stack-protector' to attribute 'optimize' [-Wattributes]
   84 | int cycrb(int l,int r,int st,int len){
      |                                     ^
necklace.cpp:84:37: warning: bad option '-f unroll-loops' to attribute 'optimize' [-Wattributes]
necklace.cpp:95:14: warning: bad option '-f no-stack-protector' to attribute 'optimize' [-Wattributes]
   95 | int ok(int mi){
      |              ^
necklace.cpp:95:14: warning: bad option '-f unroll-loops' to attribute 'optimize' [-Wattributes]
necklace.cpp:172:13: warning: bad option '-f no-stack-protector' to attribute 'optimize' [-Wattributes]
  172 | signed main()
      |             ^
necklace.cpp:172:13: warning: bad option '-f unroll-loops' to attribute 'optimize' [-Wattributes]

• Subtask 1: 5 / 25
• Subtask 2: 0 / 20
• Subtask 3: 0 / 40