function kmp(s, p) { 

    var m = 0, i = 0,   
        k, j, h,  
        slen = s.length,  
        plen = p.length;  
      
    /* converting string */  
    s = s.split("");  
    p = p.split("");      
              
    /* preprocessing */  
    h = [0];  
    for ( k = 1, j = 0; k < plen; ) {  
        if ( p[k-1] === p[j] ) {  
            h[k] = j + 1;  
            k++; j++;  
        }  
        else if ( j > 0 )  
          j = h[j];  
        else   
          h[k++] = 0;  
    }   
      
    /* search operation */  
    while ( m + i < slen ) {  
        if ( s[m+i] === p[i] ) {  
            i++;  
            if ( i === plen )   
              return m;  
        }  
        else {  
            m += i - h[i];  
            if ( h[i] > -1 )   
                i = h[i];  
            else  
                i = 0;  
        }  
    }  
    return  -1;  
}