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Submission #52034

# Submission time Handle Problem Language Result Execution time Memory
52034 2018-06-23T10:34:35 Z Milki Palinilap (COI16_palinilap) C++14
46 / 100
 138 ms 29776 KB 
#include <bits/stdc++.h>
using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define TRACE(x) cerr << #x << " = " << x << endl
#define _ << " " <<

typedef long long ll;
typedef pair<int, int> point;

const ll MAXN = 1e5 + 5;
const ll MOD = 1e9 + 7;
const ll BAZA = 1307;

string s;
int h[MAXN], h_[MAXN], pot[MAXN];

void calcHash(){
    pot[0] = 1;
    h[0] = s[0];

    FOR(i, 1, (int)s.size()){
        h[i] = ((ll)h[i - 1] * BAZA + s[i]) % MOD;
        pot[i] = (ll)pot[i - 1] * BAZA % MOD;
    }

    h_[0] = s[s.size() - 1];
    for(int i = s.size() - 2, cnt = 1; i >= 0; --i, ++cnt)
        h_[cnt] = ((ll)h_[cnt - 1] * BAZA + s[i]) % MOD;
}

ll calc(ll x, ll y){
    ll k = 0;
    if(x) k = (ll)h[x - 1] * pot[y] % MOD;
    return ((((ll)h[x + y - 1] - k) % MOD) + MOD) % MOD;
}

ll calc_(ll x, ll y){
    ll k = 0;
    if(x) k = (ll)h_[x - 1] * pot[y] % MOD;
    return ((((ll)h_[x + y - 1] - k) % MOD) + MOD) % MOD;
}

ll cntDec[MAXN];
ll decrease[MAXN];
ll increase[MAXN], letInc[MAXN][30];

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0),

    cin >> s;

    calcHash();
    ll sol = 0;

    int len = (int)s.size();

    REP(i, len){
        //neparni
        ll lo = 1, hi = min(i + 1, len - i);
        while(lo < hi){
            ll mid = (lo + hi + 1) >> 1;

            if(calc(i, mid) == calc_(len - i - 1, mid))
                lo = mid;
            else
                hi = mid - 1;
        }

        cntDec[i - lo + 1] ++;
        cntDec[i + 1] -= 2;
        cntDec[i + lo + 1] ++;

        sol += lo;
        increase[i] += lo;

        ll jump = lo + 1;
        lo = 0, hi = min(i + 1, len - i) - jump;

        while(lo < hi){
            ll mid = (lo + hi + 1) >> 1;

            if(calc(i + jump, mid) == calc_(len - i + jump - 1, mid))
                lo = mid;
            else
                hi = mid - 1;
        }
        if(i + jump - 1 > 0 && i - jump + 1 > 0){
            letInc[i + jump - 1][s[i - jump + 1] - 'a'] += lo + 1;
            letInc[i - jump + 1][s[i + jump - 1] - 'a'] += lo + 1;
        }
        if(i == len - 1) continue;
        //neparni
        lo = 0, hi = max(0, min(i + 1, len - i - 1));
        while(lo < hi){
            ll mid = (lo + hi + 1) >> 1;

            if(calc(i + 1, mid) == calc_(len - i - 1, mid))
                lo = mid;
            else
                hi = mid - 1;
        }

        sol += lo;

        if(lo){
            cntDec[i - lo + 1] ++;
            cntDec[i + 1] --;
            cntDec[i + 2] --;
            cntDec[i + lo + 2] ++;
        }

        jump = lo + 1;
        lo = 0, hi = max(0LL, min(i + 1, len - i - 1) - jump);
        while(lo < hi){

            ll mid = (lo + hi + 1) >> 1;

            if(calc(i + jump + 1, mid) == calc_(len - i + jump - 1, mid))
                lo = mid;
            else
                hi = mid - 1;
        }
        if(i + jump > 0 && i - jump + 1 > 0){
            letInc[i + jump][s[i - jump + 1] - 'a'] += lo + 1;
            letInc[i - jump + 1][s[i + jump] - 'a'] += lo + 1;
        }
    }

    ll cnt = 0, curr = 0;

    REP(i, len){
        cnt += cntDec[i];
        curr += cnt;
        decrease[i] = curr;
    }

    ll best = 0;
    REP(i, len)
        REP(j, 26){
            best = max(best, increase[i] + letInc[i][j] - decrease[i]);

        }

    cout << sol + best;
}

Subtask #1
0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Incorrect 2 ms 412 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #2
0 / 37.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 1820 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
46.0 / 46.0

# Verdict Execution time Memory Grader output
1 Correct 113 ms 27784 KB Output is correct
2 Correct 81 ms 27784 KB Output is correct
3 Correct 85 ms 27852 KB Output is correct
4 Correct 107 ms 27952 KB Output is correct
5 Correct 105 ms 28196 KB Output is correct
6 Correct 104 ms 28216 KB Output is correct
7 Correct 105 ms 28320 KB Output is correct
8 Correct 67 ms 28524 KB Output is correct
9 Correct 106 ms 28596 KB Output is correct
10 Correct 111 ms 28820 KB Output is correct
11 Correct 99 ms 28820 KB Output is correct
12 Correct 133 ms 28928 KB Output is correct
13 Correct 138 ms 29000 KB Output is correct
14 Correct 111 ms 29252 KB Output is correct
15 Correct 108 ms 29480 KB Output is correct
16 Correct 97 ms 29480 KB Output is correct
17 Correct 103 ms 29480 KB Output is correct
18 Correct 105 ms 29620 KB Output is correct
19 Correct 104 ms 29776 KB Output is correct