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Submission #196874

# Submission time Handle Problem Language Result Execution time Memory
196874 2020-01-17T11:22:20 Z jovan_b Palindromic Partitions (CEOI17_palindromic) C++17
100 / 100
 283 ms 20868 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

const int MOD = 1000000007;
const int p = 41;

int hsh[1000005];
int powers[1000005];

int add(int a, int b){
    return (a+b)%MOD;
}

int mul(int a, int b){
    return ((ll)a*b)%MOD;    
}

int substring_hash(int l, int r){
    if(l == 0) return hsh[r];
    return add(hsh[r], mul(powers[r-l+1], MOD - hsh[l-1]));
}

void solve(){
    string s;
    cin >> s;
    int n = s.size();
    if(n == 1){
        cout << 1 << "\n";
        return;
    }
    powers[0] = 1;
    for(int i=1; i<=n; i++) powers[i] = mul(p, powers[i-1]);
    hsh[0] = 1 + (s[0] - 'a');
    for(int i=1; i<n; i++){
        hsh[i] = add(mul(p, hsh[i-1]), (s[i]-'a') + 1);
    }
    int l1=0, r1=0, l2=n-1, r2=n-1;
    int res = 0;
    while(1){
        //cout << l1 << " " << r1 << " " << l2 << " " << r2 << endl;
        //cout << substring_hash(l1, r1) << " " << substring_hash(l2, r2) << endl;
        if(substring_hash(l1, r1) == substring_hash(l2, r2)){
            res += 2;
            r2 = l2-1;
            l1 = r1+1;
            r1++;
            l2--;
            if(r1 > l2){
                cout << res << "\n";
                return;
            }
            if(r1 == l2){
                cout << res+1 << "\n";
                return;
            }
        }
        else{
            r1++;
            l2--;
            if(r1 >= l2){
                cout << res+1 << "\n";
                return;
            }
        }
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cout.precision(10);
    cout << fixed;
    
    int t;
    cin >> t;
    while(t--){
        solve();
    }
    return 0;
}

Subtask #1
15.0 / 15.0

# 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 Correct 2 ms 376 KB Output is correct
4 Correct 7 ms 348 KB Output is correct
5 Correct 2 ms 376 KB Output is correct

Subtask #2
20.0 / 20.0

# 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 Correct 2 ms 376 KB Output is correct
4 Correct 7 ms 348 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 9 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct

Subtask #3
25.0 / 25.0

# 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 Correct 2 ms 376 KB Output is correct
4 Correct 7 ms 348 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 9 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 9 ms 632 KB Output is correct
11 Correct 4 ms 504 KB Output is correct
12 Correct 5 ms 504 KB Output is correct
13 Correct 5 ms 504 KB Output is correct

Subtask #4
40.0 / 40.0

# 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 Correct 2 ms 376 KB Output is correct
4 Correct 7 ms 348 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 9 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 9 ms 632 KB Output is correct
11 Correct 4 ms 504 KB Output is correct
12 Correct 5 ms 504 KB Output is correct
13 Correct 5 ms 504 KB Output is correct
14 Correct 283 ms 20868 KB Output is correct
15 Correct 154 ms 15800 KB Output is correct
16 Correct 280 ms 19980 KB Output is correct
17 Correct 158 ms 11220 KB Output is correct