Submission #229914

#	Time	Username	Problem	Language	Result	Execution time	Memory
229914		mohamedsobhi777	Rima (COCI17_rima)	C++14	28 / 140	1104 ms	116948 KiB

rima

#include<bits/stdc++.h>

using namespace std ; 


const int N = 5e5 + 7 ; 

int n ; 
int dp[N] ; 
int ans ; 
string ss[N] ; 


struct hashing {
    long long base ; 
    long long mod1;
    vector<long long> pref; 
    vector<long long> base_power; 

    long long normalize(long long x ){
        return ((x%mod1) + mod1) %mod1 ; 
    }
    string s ; 
    void init(string &str_,long long mod1_ = 1e9 +7, long long base_ = 313){

        int sz = str_.size() ; 
        pref.resize(sz) ; 
        base_power.resize(sz) ;
        base = base_ ; 
        mod1 = mod1_ ; 
        s = str_ ; 
        base_power[0] = 1 ; 
        for(int i = 1 ;i <sz ; i++){
            base_power[i] = (1ll*base*base_power[i-1]) %mod1 ; 
        }

        long long cur = 0 ; 
        for(int i = 0 ; i <sz ; i++){
            cur = (cur*base + str_[i])%mod1;
            pref[i] = cur ; 
        } 
    }

    long long get(int l , int r){
        r-- ;
        long long ret = pref[r] ; 
        if(l){
            long long power_difference = base_power[r-l+1]; 
            long long prefix_hash =pref[l-1];
            prefix_hash = (prefix_hash*power_difference)%mod1 ; 
            ret = normalize(ret - prefix_hash) ; 
        }           

        return ret ; 
    }
}  shs[N] ;

bool match(int i , int j){
    if(ss[i] .size() > ss[j].size()) return match(j , i) ; 
    if( abs( (int) ss[i].size() - (int) ss[j].size()) > 1 )  return 0 ; 
    if(shs[i].get(0 , ss[i].size() ) == shs[j].get(0 , ss[j].size())) return 1 ; 
    int k = ss[j] .size() - 1 ; 
    return (shs[i].get(0 , k)  == shs[j].get(0 , k  ) ); 
}

int main(){
    ios_base::sync_with_stdio(0) ; 
    cin.tie(0) ; 
    //freopen("in.in" , "r" , stdin) ; 
    cin>>n ; 
    for(int i = 0 ; i < n ;i++){
        cin>>ss[i] ;
        reverse( ss[i] .begin() , ss[i].end()) ; 
    }
    sort(ss , ss + n) ;
    for(int i = 0   ; i < n; i++){
        shs[i].init(ss[i]) ; 
    }
    for(int i = 0 ;i < n ;i++){ 
        dp[i] = 1 ; 
        for(int j = 0 ; j < i ; j++){
            if(match(j , i)){
                dp[i] = max(dp[i] , dp[j]+1) ; 
            }
        }
        ans = max(ans , dp[i]) ; 
    }
    cout<< ans ; 
    return 0 ;
}

• Subtask 1: 28 / 140