Finder-Mck

package com.company;

/**
 * Finder utitilies
 */
public class Finder {

  /**
   *
   * @param smallArray Represents the subset array to be found
   * @param bigArray Represents the set in which to find the array
   * @return int This returns the index of the first element if subset of is found else -1
   */
  public int find(char[] smallArray, char[] bigArray){
    int result = -1;
    //step1 boundary conditions
    if(bigArray.length == 0 || smallArray.length ==0){
      return result;
    }
    if(bigArray.length < smallArray.length) {
      return result;
    }

    //small array is considered to be a block, so check till the start only
    int len = bigArray.length - smallArray.length;

    for (int i = 0; i <= len; i++) {
      if( bigArray[i] == smallArray[0] && isSequence(smallArray, bigArray, i)){
        return i;
      }
    }
    return result;
  }

  private boolean isSequence(char[] smallArray, char[] bigArray, int index){
    boolean isValid = true;
    for (int i=1; i<smallArray.length; i++){
      if(bigArray[index+i] != smallArray[i]){
        isValid = false;
        break;
      }
    }
    return isValid;
  }
}