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Submission #250646

# Submission time Handle Problem Language Result Execution time Memory
250646 2020-07-18T15:04:07 Z Sorting Palindromic Partitions (CEOI17_palindromic) C++14
60 / 100
 10000 ms 22044 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int k_N = 1e6 + 3;
const int cnt_Mod = 1;
const array<ll, cnt_Mod> k_Mod{(int)1e9 + 7}, k_Base{293};

int dp[k_N];
string s;
int n;

array<ll, cnt_Mod> h[k_N], b_pow[k_N];
vector<int> pos[256];
int idx[256];

ll get_hash(int l, int r, int idx){
    if(l == 0) return h[r][idx];
    ll ans = (h[r][idx] - h[l - 1][idx] * b_pow[r - l + 1][idx]) % k_Mod[idx];
    return (ans < 0) ? (ans + k_Mod[idx]) : ans;
}

bool equal(int l1, int r1, int l2, int r2){
    for(int i = 0; i < cnt_Mod; ++i)
        if(get_hash(l1, r1, i) != get_hash(l2, r2, i))
            return false;
    return true;
}

void init_hashing(){
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < cnt_Mod; ++j){
            if(i == 0)
                h[i][j] = s[i];
            else
                h[i][j] = (h[i - 1][j] * k_Base[j] + s[i]) % k_Mod[j];
        }
    }

    for(int i = 0; i < n; ++i){
        for(int j = 0; j < cnt_Mod; ++j){
            if(i == 0)
                b_pow[i][j] = 1;
            else
                b_pow[i][j] = b_pow[i - 1][j] * k_Base[j] % k_Mod[j];
        }
    }
}

void solve(){
    cin >> s;
    n = (int)s.size();

    if(n == 1){
        cout << "1\n";
        return;
    }


    init_hashing();
    for(int i = 0; i < n; ++i)
        pos[s[i]].push_back(i);

    int mid = (n - 1) / 2, mid2 = (n - 2) / 2;
    dp[mid + 1] = 0;
    for(int i = mid; i >= 0; --i){
        dp[i] = 1;
        for(int k = (int)pos[s[i]].size() - 1; k >= 0; --k){
            int j = pos[s[i]][k];
            if(j > n - i - 1) continue;
            if(n - j - 1 >= j) break;

            if(dp[n - j] + 2 <= dp[i]) break;

            if(equal(i, n - j - 1, j, n - i - 1)){
                dp[i] = max(dp[n - j] + 2, dp[i]);
                break;
            }
        }
    }

    cout << dp[0] << "\n";
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL);

    int t;
    cin >> t;

    while(t--)
        solve();
}

Compilation message

palindromic.cpp: In function 'void solve()':
palindromic.cpp:64:17: warning: array subscript has type 'char' [-Wchar-subscripts]
         pos[s[i]].push_back(i);
                 ^
palindromic.cpp:70:34: warning: array subscript has type 'char' [-Wchar-subscripts]
         for(int k = (int)pos[s[i]].size() - 1; k >= 0; --k){
                                  ^
palindromic.cpp:71:29: warning: array subscript has type 'char' [-Wchar-subscripts]
             int j = pos[s[i]][k];
                             ^
palindromic.cpp:66:28: warning: unused variable 'mid2' [-Wunused-variable]
     int mid = (n - 1) / 2, mid2 = (n - 2) / 2;
                            ^~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 1 ms 384 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 1 ms 384 KB Output is correct
10 Correct 80 ms 1156 KB Output is correct
11 Correct 132 ms 1016 KB Output is correct
12 Correct 63 ms 1140 KB Output is correct
13 Correct 42 ms 1016 KB Output is correct

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 0 ms 384 KB Output is correct
5 Correct 0 ms 384 KB Output is correct
6 Correct 0 ms 384 KB Output is correct
7 Correct 1 ms 384 KB Output is correct
8 Correct 1 ms 384 KB Output is correct
9 Correct 1 ms 384 KB Output is correct
10 Correct 80 ms 1156 KB Output is correct
11 Correct 132 ms 1016 KB Output is correct
12 Correct 63 ms 1140 KB Output is correct
13 Correct 42 ms 1016 KB Output is correct
14 Execution timed out 10014 ms 22044 KB Time limit exceeded
15 Halted 0 ms 0 KB -