HDU 3856 Palindrome ( Manacher + RMQ + 二分 ) WA！！！

不知道错在哪了，求大神指教！！！

思路：用manacher求出每个以str[i]为中心轴的回文串的长度，RMQ预处理区间最大值，对于每个查询，二分最大回文串长，判定是否可行。

 

#include <cstdio>

#include <cstring>

#include <cstdlib>

#include <algorithm>



using namespace std;



const int MAXN = 222222;



char str[ MAXN ];

int data[ MAXN * 2 ];

int p[ MAXN * 2 ];

int d[ MAXN * 2 ][30];

int n, len;



void init()

{

    int id,MaxL,MaxId;

    int i;

    MaxL=MaxId=0;

    len = strlen(&str[1]);

    for (i=1; i <= len; i++)

    {

        data[(i<<1)]=str[i];

        data[(i<<1)+1]=2;

    }

    data[0]=1;

    data[1]=2;

    n=(i<<1)+2;

    data[n]=0;

    MaxId=MaxL=0;

    p[0] = 1;

    for (i=1; i<n; i++)

    {

        if (MaxId>i)

            p[i]=min(p[2*id-i],MaxId-i);

        else

            p[i]=1;

        while (data[i+p[i]] == data[i-p[i]])

            p[i]++;

        if (p[i]+i>MaxId)

            MaxId=p[i]+i,id=i;

        //printf( "p[%d]=%d\n", i, p[i] );

    }

    for ( i = 1; i < n; ++i ) --p[i];



    return;

}



void RMQinit()

{

    for ( int i = 0; i <= n; ++i ) d[i][0] = p[i];

    for ( int j = 1; ( 1 << j ) <= n; ++j )

        for ( int i = 1; i + j - 1 <= n; ++i )

            d[i][j] = max( d[i][j - 1], d[ i + (1<<(j-1))][j - 1] );

    return;

}



int RMQquery( int L, int R )

{

    int k = 0;

    while ( (1 << (k + 1)) <= R - L + 1 ) ++k;

    return max( d[L][k], d[ R - ( 1 << k ) + 1 ][k] );

}



bool check( int L, int R, int mid )

{

    //if ( L + mid > R - mid ) return false;

    int ans = RMQquery( L + mid, R - mid );

    //printf("[%d %d]:%d\n", L + mid, R - mid, ans );

    //printf("ans = %d, mid = %d\n", ans, mid );

    if ( ans >= mid )

    {

        //puts("****");

        return true;

    }

    return false;

}



int BiSearch( int l, int r, int L, int R )

{

    int ans = 1;

    while ( l <= r )

    {

        int mid = ( l + r ) >> 1;

        if ( check( L, R, mid ) )

        {

            l = mid + 1;

            ans = mid;

        }

        else r = mid - 1;

    }

    return ans;

}



int main()

{

    int T;

    scanf( "%d", &T );

    getchar();

    while ( T-- )

    {

        memset( d, 0, sizeof(d) );

        memset( p, 0, sizeof(p) );

        gets( &str[1] );

        init();

        RMQinit();



        int Q;

        scanf( "%d", &Q );

        while ( Q-- )

        {

            int a, b;

            scanf( "%d%d", &a, &b );

            if ( a < 1 ) a = 1;

            if ( b > len ) b = len;

            if ( a > len )

            {

                puts("0");

                continue;

            }

            if ( a > b ) swap( a, b );

            int ans = BiSearch( 1, b - a + 1, a*2 - 1, b*2 + 1 );

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

        }

        getchar();

    }

    return 0;

}