Submission #77600

#	Time	Username	Problem	Language	Result	Execution time	Memory
77600		duality	Palindromic Partitions (CEOI17_palindromic)	C++11	60 / 100	10044 ms	25840 KiB

palindromic

#define DEBUG 0

#include <bits/stdc++.h>
using namespace std;

#if DEBUG
// basic debugging macros
int __i__,__j__;
#define printLine(l) for(__i__=0;__i__<l;__i__++){cout<<"-";}cout<<endl
#define printLine2(l,c) for(__i__=0;__i__<l;__i__++){cout<<c;}cout<<endl
#define printVar(n) cout<<#n<<": "<<n<<endl
#define printArr(a,l) cout<<#a<<": ";for(__i__=0;__i__<l;__i__++){cout<<a[__i__]<<" ";}cout<<endl
#define print2dArr(a,r,c) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<a[__i__][__j__]<<" ";}cout<<endl;}
#define print2dArr2(a,r,c,l) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<setw(l)<<setfill(' ')<<a[__i__][__j__]<<" ";}cout<<endl;}

// advanced debugging class
// debug 1,2,'A',"test";
class _Debug {
    public:
        template<typename T>
        _Debug& operator,(T val) {
            cout << val << endl;
            return *this;
        }
};
#define debug _Debug(),
#else
#define printLine(l)
#define printLine2(l,c)
#define printVar(n)
#define printArr(a,l)
#define print2dArr(a,r,c)
#define print2dArr2(a,r,c,l)
#define debug
#endif

// define
#define MAX_VAL 999999999
#define MAX_VAL_2 999999999999999999LL
#define EPS 1e-6
#define mp make_pair
#define pb push_back

// typedef
typedef unsigned int UI;
typedef long long int LLI;
typedef unsigned long long int ULLI;
typedef unsigned short int US;
typedef pair<int,int> pii;
typedef pair<LLI,LLI> plli;
typedef vector<int> vi;
typedef vector<LLI> vlli;
typedef vector<pii> vpii;
typedef vector<plli> vplli;

// ---------- END OF TEMPLATE ----------
#define MOD 1000000007
#define S1 23
#define S2 31

char s[1000001];
int n,dp[1000000];
int pow1[1000000],pow2[1000000];
int h1[1000000],h2[1000000];
pii getHash(int s,int e) {
    return mp(((LLI) (h1[e]-((s == 0) ? 0:h1[s-1])+MOD)*pow1[n-s-1]) % MOD,
              ((LLI) (h2[e]-((s == 0) ? 0:h2[s-1])+MOD)*pow2[n-s-1]) % MOD);
}
int main() {
    int i,j,k;
    int t;
    scanf("%d",&t);
    for (i = 0; i < t; i++) {
        scanf("%s",s);
        n = strlen(s);

        pow1[0] = pow2[0] = 1;
        for (j = 1; j < n; j++) {
            pow1[j] = ((LLI) pow1[j-1]*S1) % MOD;
            pow2[j] = ((LLI) pow2[j-1]*S2) % MOD;
        }
        for (j = 0; j < n; j++) {
            h1[j] = ((LLI) pow1[j]*s[j]) % MOD;
            h2[j] = ((LLI) pow2[j]*s[j]) % MOD;
            if (j > 0) {
                h1[j] += h1[j-1],h1[j] %= MOD;
                h2[j] += h2[j-1],h2[j] %= MOD;
            }
        }

        int ans = 1;
        for (j = 0; j < n/2; j++) {
            int m = -MAX_VAL;
            for (k = j; k >= 0; k--) {
                if (getHash(k,j) == getHash(n-j-1,n-k-1)) {
                    m = (k == 0) ? 0:dp[k-1];
                    break;
                }
            }
            dp[j] = m+1;
            ans = max(ans,2*dp[j]+((2*(j+1) == n) ? 0:1));
        }
        printf("%d\n",ans);
    }

    return 0;
}

Compilation message (stderr)

palindromic.cpp: In function 'int main()':
palindromic.cpp:72:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&t);
     ~~~~~^~~~~~~~~
palindromic.cpp:74:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%s",s);
         ~~~~~^~~~~~~~

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