Submission #657115

# Submission time Handle Problem Language Result Execution time Memory
657115 2022-11-08T21:59:53 Z inksamurai Necklace (Subtask 1-3) (BOI19_necklace1) C++17
45 / 85
81 ms 692 KB
#include <bits/stdc++.h>

// cut here
#ifdef _MSC_VER
#include <intrin.h>
#endif
 
namespace atcoder {
 
namespace internal {
 
int ceil_pow2(int n) {
    int x = 0;
    while ((1U << x) < (unsigned int)(n)) x++;
    return x;
}
 
int bsf(unsigned int n) {
#ifdef _MSC_VER
    unsigned long index;
    _BitScanForward(&index, n);
    return index;
#else
    return __builtin_ctz(n);
#endif
}
 
}  // namespace internal
 
}  // namespace atcoder
 
 
namespace atcoder {
 
template <class S, S (*op)(S, S), S (*e)()> struct segtree {
  public:
    segtree() : segtree(0) {}
    segtree(int n) : segtree(std::vector<S>(n, e())) {}
    segtree(const std::vector<S>& v) : _n(int(v.size())) {
        log = internal::ceil_pow2(_n);
        size = 1 << log;
        d = std::vector<S>(2 * size, e());
        for (int i = 0; i < _n; i++) d[size + i] = v[i];
        for (int i = size - 1; i >= 1; i--) {
            update(i);
        }
    }
 
    void set(int p, S x) {
        assert(0 <= p && p < _n);
        p += size;
        d[p] = x;
        for (int i = 1; i <= log; i++) update(p >> i);
    }
 
    S get(int p) {
        assert(0 <= p && p < _n);
        return d[p + size];
    }
 
    S prod(int l, int r) {
        assert(0 <= l && l <= r && r <= _n);
        S sml = e(), smr = e();
        l += size;
        r += size;
 
        while (l < r) {
            if (l & 1) sml = op(sml, d[l++]);
            if (r & 1) smr = op(d[--r], smr);
            l >>= 1;
            r >>= 1;
        }
        return op(sml, smr);
    }
 
    S all_prod() { return d[1]; }
 
    template <bool (*f)(S)> int max_right(int l) {
        return max_right(l, [](S x) { return f(x); });
    }
    template <class F> int max_right(int l, F f) {
        assert(0 <= l && l <= _n);
        assert(f(e()));
        if (l == _n) return _n;
        l += size;
        S sm = e();
        do {
            while (l % 2 == 0) l >>= 1;
            if (!f(op(sm, d[l]))) {
                while (l < size) {
                    l = (2 * l);
                    if (f(op(sm, d[l]))) {
                        sm = op(sm, d[l]);
                        l++;
                    }
                }
                return l - size;
            }
            sm = op(sm, d[l]);
            l++;
        } while ((l & -l) != l);
        return _n;
    }
 
    template <bool (*f)(S)> int min_left(int r) {
        return min_left(r, [](S x) { return f(x); });
    }
    template <class F> int min_left(int r, F f) {
        assert(0 <= r && r <= _n);
        assert(f(e()));
        if (r == 0) return 0;
        r += size;
        S sm = e();
        do {
            r--;
            while (r > 1 && (r % 2)) r >>= 1;
            if (!f(op(d[r], sm))) {
                while (r < size) {
                    r = (2 * r + 1);
                    if (f(op(d[r], sm))) {
                        sm = op(d[r], sm);
                        r--;
                    }
                }
                return r + 1 - size;
            }
            sm = op(d[r], sm);
        } while ((r & -r) != r);
        return 0;
    }
 
  private:
    int _n, size, log;
    std::vector<S> d;
 
    void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); }
};
 
}  // namespace atcoder
// cut here 

using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define rng(i,c,n) for(int i=c;i<n;i++)
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define vec(...) vector<__VA_ARGS__>
#define _3NRqilq ios::sync_with_stdio(0),cin.tie(0)
typedef long long ll;
using pii=pair<int,int>;
using vi=vector<int>;
void print(){cout<<'\n';}
template<class h,class...t>
void print(const h&v,const t&...u){cout<<v<<' ',print(u...);}

// snuke's mod int
template <ll mod>
struct modint{
	ll x;
	modint(ll x=0):x((x%mod+mod)%mod){}
	modint operator-()const{return modint(-x);}
	modint& operator+=(const modint a){if((x+=a.x)>=mod) x-=mod; return *this;}
	modint& operator-=(const modint a){if((x+=mod-a.x)>=mod) x-=mod; return *this;}
	modint& operator*=(const modint a){(x*=a.x)%=mod; return *this;}
	modint operator+(const modint a)const{modint res(*this); return res+=a;}
	modint operator-(const modint a)const{modint res(*this); return res-=a;}
	modint operator*(const modint a)const{modint res(*this); return res*=a;}
	modint pow(ll n)const{
		modint res=1,x(*this);
		while(n){
			if(n&1)res*=x;
			x*=x;
			n>>=1;
		}
		return res;
	}
	modint inv()const{return pow(mod-2);}
};

// include mint here
using hshmint=modint<1000000007>;
using hshmint1=modint<998244353>;
using magicpair=pair<hshmint,hshmint1>;
struct rollhsh{	
	hshmint _p=9973; // base
	hshmint1 _p1=257; // base1
	vec(hshmint) pw,invpw;
	vec(hshmint1) pw1,invpw1;
	vec(magicpair) hsh;
	rollhsh(string s=""){
		init(s);
	}
	void init(string s){
		// put this out in global if multiple testcases
		hsh.clear();
		pw.clear();
		invpw.clear();
		pw1.clear();
		invpw1.clear();
		hsh.resize(sz(s)+1);
		pw.resize(sz(s)+1);
		invpw.resize(sz(s)+1);
		pw1.resize(sz(s)+1);
		invpw1.resize(sz(s)+1);
		hsh[0]={1,1};
		pw[0]=1;
		pw1[0]=1;
		invpw[0]=1;
		invpw1[0]=1;		
		hshmint _invbase=_p.x;
		hshmint1 _invbase1=_p1.x;
		_invbase=_invbase.inv(); _invbase1=_invbase1.inv();
		rep(i,sz(s)){
			pw[i+1]=pw[i]*_p;
			pw1[i+1]=pw1[i]*_p1;
			invpw[i+1]=invpw[i]*_invbase;
			invpw1[i+1]=invpw1[i]*_invbase1;
			hshmint x=(int)(s[i]-'a'+1);
			hshmint1 x1=(int)(s[i]-'a'+1);
			hsh[i+1]={hsh[i].fi+pw[i]*x,hsh[i].se+pw1[i]*x1};
		}
	}
	pair<ll,ll> get(int l,int r){ 
		// from - to , inclusive
		hshmint _f=invpw[l]*(hsh[r+1].fi-hsh[l].fi);
		hshmint1 _s=invpw1[l]*(hsh[r+1].se-hsh[l].se);
		return {_f.x,_s.x};	
	}
};

#define all(a) a.begin(),a.end()

vi eval_pf(string s){
	int n=sz(s);
	vi pf(n);
	rng(i,1,n){
		int j=pf[i-1];
		while(j and s[i]!=s[j]){
			j=pf[j-1];
		}
		j+=(s[i]==s[j]);
		pf[i]=j;
	}
	return pf;
}

vi eval_pf1(string s){
	int n=sz(s);
	rollhsh hsh(s); // please don't tle
	vi pf(n);
	int frm=-1;
	rep(i,n){
		if(s[i]=='.'){
			frm=i;
		}
	}
	frm++;
	rng(i,frm,n){
		int l=1,r=n-i;
		int c=0;
		while(l<=r){
			int m=(l+r)/2;
			if(hsh.get(0,m-1)==hsh.get(i,i+m-1)){
				c=m,l=m+1;
			}else{
				r=m-1;
			}
		}
		pf[i]=c;
	}
	return pf;
}

pii op(pii l,pii r){return l.fi>r.fi?l:r;}
pii e(){return {0,-1};}

signed main(){
_3NRqilq;	
	string s;
	cin>>s;
	string t;
	cin>>t;
	string rt=t;
	reverse(all(rt));
	int n=sz(s);
	int m=sz(t);
	int len=0;
	pii p={0,0};
	rep(_,2){
		rep(i,n)
		{
			vi a(m);
			if(i<n-1){
				string cur=s.substr(i+1,n-i-1);
				cur+=".";
				cur+=rt;
				auto pfa=eval_pf(cur);
				rng(j,n-i,sz(cur)){
					a[m-(j-(n-i))-1]=pfa[j];
				}
			}
			vi b(m);
			if(i){
				string cur="";
				cur+=s.substr(0,i);
				reverse(all(cur));
				cur+=".";
				cur+=t;
				vi pfb(m,0);
				if(n+m<3000){
					pfb=eval_pf1(cur);
				}
				rng(j,i+1,sz(cur)){
					b[j-(i+1)]=pfb[j];
				}
			}
			atcoder::segtree<pii,op,e> seg(m+1);
			rep(i,m+1){
				if(i==m){
					seg.set(i,{m,i});
				}else{
					seg.set(i,{a[i]+i,i});
				}
			}
			rep(j,m){
				if(s[i]==t[j]){
					if(j+1<m){
						int frm=j+1;
						int to=frm+b[frm]-1;
						pii q=seg.prod(frm,to+2);
						int now=q.fi-frm+1;
						if(now>len){
							len=now;
							int ni=i-(q.se-frm);
							p={ni,j};
							if(_==1){
								p={n-ni-now,j};
							}
						}
					}
					{
						int now=1;
						if(now>len){
							len=now;
							int ni=i;
							p={ni,j};
							if(_==1){
								p={n-ni-now,j};
							}
						}
					}
				}
			}		
		}
		reverse(all(s));
	}
	cout<<len<<"\n";
	cout<<p.fi<<" "<<p.se<<"\n";
}
# Verdict Execution time Memory Grader output
1 Correct 5 ms 340 KB Output is correct
2 Correct 4 ms 340 KB Output is correct
3 Correct 4 ms 340 KB Output is correct
4 Correct 4 ms 340 KB Output is correct
5 Correct 4 ms 340 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 5 ms 340 KB Output is correct
2 Correct 4 ms 340 KB Output is correct
3 Correct 4 ms 340 KB Output is correct
4 Correct 4 ms 340 KB Output is correct
5 Correct 4 ms 340 KB Output is correct
6 Correct 81 ms 404 KB Output is correct
7 Correct 72 ms 340 KB Output is correct
8 Correct 66 ms 468 KB Output is correct
9 Correct 68 ms 420 KB Output is correct
10 Correct 65 ms 340 KB Output is correct
11 Correct 75 ms 416 KB Output is correct
12 Correct 74 ms 376 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 5 ms 340 KB Output is correct
2 Correct 4 ms 340 KB Output is correct
3 Correct 4 ms 340 KB Output is correct
4 Correct 4 ms 340 KB Output is correct
5 Correct 4 ms 340 KB Output is correct
6 Correct 81 ms 404 KB Output is correct
7 Correct 72 ms 340 KB Output is correct
8 Correct 66 ms 468 KB Output is correct
9 Correct 68 ms 420 KB Output is correct
10 Correct 65 ms 340 KB Output is correct
11 Correct 75 ms 416 KB Output is correct
12 Correct 74 ms 376 KB Output is correct
13 Runtime error 15 ms 692 KB Execution killed with signal 6
14 Halted 0 ms 0 KB -