Submission #116253

#	Time	Username	Problem	Language	Result	Execution time	Memory
116253		Meloric	Palindromic Partitions (CEOI17_palindromic)	C++14	0 / 100	2 ms	384 KiB

palindromic

#include <bits/stdc++.h>
#define pb push_back
#define X first
#define Y second
#define pii pair<int, int>
#define int int64_t
#define pow pww
using namespace std;
int mod = 1e9+7;
vector<int>hsh, pow;

bool same(int l, int r, int len, vector<int>&wrd){
    for(int i = 0; i<=len; i++){
        if(wrd[l+i] != wrd[r+i-len])return false;
    }
    return true;
}
int hval(int l, int r){
    int ans;
    r++;
    ans = hsh[r] - hsh[l]*pow[r-l+1];
    ans %= mod;
    if(ans<0)ans+=mod;
    return ans;
}
int dp(int l, int r, vector<int>&wrd){
    if(r<l)return 0;
    for(int i = 0; i+l < r-i ;i++){
        if(hval(l, l+i) == hval(r-i, r) && same(l, r, i, wrd))return dp(l+i+1, r-i-1, wrd)+2;
    }
    return 1;
}
void solve(){
    hsh.clear(); pow.clear();
    string in; vector<int> wrd;
    cin >> in;
    for(auto i : in)wrd.pb(i-'a');
    pow.pb(0); hsh.pb(0); pow.pb(1);
    for(int i = 0; i < wrd.size(); i++){
        hsh.pb(hsh.back()*31+wrd[i]);
        hsh.back()%=mod;
        pow.pb(pow.back()*31);
    }
    //for(int i : wrd)cout << i <<' ';
    cout << dp(0, wrd.size()-1, wrd)<< '\n';
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int t; cin >> t;
    while(t--){
        solve();
    }
    return 0;
}

Compilation message (stderr)

palindromic.cpp: In function 'void solve()':
palindromic.cpp:39:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 0; i < wrd.size(); i++){
                    ~~^~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 20
• Subtask 3: 0 / 25
• Subtask 4: 0 / 40