I have a task : "Jewish-style carp"
Devise a version of Rabin-Karp algorithm which will check if for a given
picture* M by N large its top-right K by K corner is duplicated somewhere in the picture.
Your algorithm should replace slow modulo prime operations with faster bitwise mask &'s.
!!!! Do make sure that the RT is at most linear in the number of pixels in the text !!!
* Here, picture is a two-dimensional array of arbitrary items.
and I write the code m= mask value and B= Base value
public static boolean hasDuplicateCorner(int[][] picture, int K) {
int M = (1 << K) - 1; // Mask value
int B = 31; // Base value
Map<Integer, Boolean> hashTable = new HashMap<>();
// Compute hash value of the top-right KxK corner
int cornerHash = 0;
for (int row = 0; row < K; row++) {
for (int col = picture[row].length - K; col < picture[row].length; col++) {
cornerHash = ((cornerHash << 1) + picture[row][col]) & M;
}
}
hashTable.put(cornerHash, true);
// Iterate over the remaining elements of the picture
for (int row = 0; row <= picture.length - K; row++) {
for (int col = 0; col <= picture[row].length - K; col++) {
// Compute hash value of the current KxK corner
int currentHash = 0;
for (int i = row; i < row + K; i++) {
for (int j = col; j < col + K; j++) {
currentHash = ((currentHash << 1) + picture[i][j]) & M;
}
}
// Check if the current hash value already exists in the hash table
if (hashTable.containsKey(currentHash)) {
return true; // Duplicate corner found
}
// Add the current hash value to the hash table
hashTable.put(currentHash, true);
}
}
return false; // No duplicate corner found
}
but it didn't work for all inputs.
How can I solve this problem, and I asked AI but it didn't work too