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답안 #122362

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
122362 2019-06-28T05:48:27 Z BThero Palindromic Partitions (CEOI17_palindromic) C++17
100 / 100
 166 ms 17152 KB 
// Why am I so dumb? :c
// chrono::system_clock::now().time_since_epoch().count()

//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>

#define pb push_back
#define mp make_pair

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

#define fi first
#define se second

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;   
typedef pair<int, int> pii;
template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const int MAXN = (int)1e6 + 5;
const int INF = (int)1e9;
const int MOD = (int)1e9 + 7;
const int MOD2 = (int)1e9 + 9;
const int P = 31;
const int P2 = 37;

int pref[MAXN], pref2[MAXN];

int PW[MAXN], PW2[MAXN];

char s[MAXN];

int n, ans;

int addMod(int a, int b, int m) {
    a += b;

    if (m <= a) {
        a -= m;
    }

    return a;
}

int mulMod(int a, int b, int m) {
    return a * 1ll * b % m;
}

void pre() {
    PW[0] = 1;
    PW2[0] = 1;

    for (int i = 1; i < MAXN; ++i) {
        PW[i] = mulMod(PW[i - 1], P, MOD);
        PW2[i] = mulMod(PW2[i - 1], P2, MOD2);
    }
}

bool good(int l, int r) {
    int l2 = n - r + 1;
    int r2 = n - l + 1;

    int a1 = addMod(pref[r], MOD - pref[l - 1], MOD);
    int a2 = addMod(pref2[r], MOD2 - pref2[l - 1], MOD2);

    int b1 = addMod(pref[r2], MOD - pref[l2 - 1], MOD);
    int b2 = addMod(pref2[r2], MOD2 - pref2[l2 - 1], MOD2);

    a1 = mulMod(a1, PW[n - l], MOD);
    a2 = mulMod(a2, PW2[n - l], MOD2);
    b1 = mulMod(b1, PW[n - l2], MOD);
    b2 = mulMod(b2, PW2[n - l2], MOD2);

    return a1 == b1 && a2 == b2;
}

void solve() {
    scanf("%s", s + 1);         
    for (n = 1; s[n]; ++n);     

    --n;
    ans = 0;

    for (int i = 1; i <= n; ++i) {
        pref[i] = addMod(pref[i - 1], mulMod(s[i] - 'a' + 1, PW[i], MOD), MOD);
        pref2[i] = addMod(pref2[i - 1], mulMod(s[i] - 'a' + 1, PW2[i], MOD2), MOD2);
    }    

    for (int l = 1, r; l <= n; l = r + 1) {
        r = l;

        while (r * 2 <= n && !good(l, r)) {
            ++r;
        }

        if (r * 2 > n) {
            ++ans;
            break;            
        }

        ans += 2;

        if (r * 2 == n) {
            break;
        }                               
    }    

    printf("%d\n", ans);
}

int main() {
    int tt;
    scanf("%d", &tt);
    
    pre();

    while (tt--) {
        solve();
    }

    return 0;
}

Compilation message

palindromic.cpp: In function 'void solve()':
palindromic.cpp:84:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s", s + 1);         
     ~~~~~^~~~~~~~~~~~~
palindromic.cpp: In function 'int main()':
palindromic.cpp:119:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &tt);
     ~~~~~^~~~~~~~~~~

Subtask #1
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 8192 KB Output is correct
2 Correct 13 ms 8192 KB Output is correct
3 Correct 13 ms 8192 KB Output is correct
4 Correct 14 ms 8192 KB Output is correct
5 Correct 13 ms 8192 KB Output is correct

Subtask #2
20.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 8192 KB Output is correct
2 Correct 13 ms 8192 KB Output is correct
3 Correct 13 ms 8192 KB Output is correct
4 Correct 14 ms 8192 KB Output is correct
5 Correct 13 ms 8192 KB Output is correct
6 Correct 13 ms 8192 KB Output is correct
7 Correct 13 ms 8192 KB Output is correct
8 Correct 13 ms 8192 KB Output is correct
9 Correct 16 ms 8192 KB Output is correct

Subtask #3
25.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 8192 KB Output is correct
2 Correct 13 ms 8192 KB Output is correct
3 Correct 13 ms 8192 KB Output is correct
4 Correct 14 ms 8192 KB Output is correct
5 Correct 13 ms 8192 KB Output is correct
6 Correct 13 ms 8192 KB Output is correct
7 Correct 13 ms 8192 KB Output is correct
8 Correct 13 ms 8192 KB Output is correct
9 Correct 16 ms 8192 KB Output is correct
10 Correct 15 ms 8192 KB Output is correct
11 Correct 14 ms 8448 KB Output is correct
12 Correct 14 ms 8192 KB Output is correct
13 Correct 15 ms 8320 KB Output is correct

Subtask #4
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 8192 KB Output is correct
2 Correct 13 ms 8192 KB Output is correct
3 Correct 13 ms 8192 KB Output is correct
4 Correct 14 ms 8192 KB Output is correct
5 Correct 13 ms 8192 KB Output is correct
6 Correct 13 ms 8192 KB Output is correct
7 Correct 13 ms 8192 KB Output is correct
8 Correct 13 ms 8192 KB Output is correct
9 Correct 16 ms 8192 KB Output is correct
10 Correct 15 ms 8192 KB Output is correct
11 Correct 14 ms 8448 KB Output is correct
12 Correct 14 ms 8192 KB Output is correct
13 Correct 15 ms 8320 KB Output is correct
14 Correct 166 ms 17016 KB Output is correct
15 Correct 100 ms 17152 KB Output is correct
16 Correct 156 ms 17016 KB Output is correct
17 Correct 94 ms 12848 KB Output is correct