Find substring given string using BigO n algorithm

Find substring given string using BigO n algorithm

Write a method to find a substring in a given string. Do this in O(n) or better.

Solution: Below java program is using O(n) Brute Force algorithm to find substring in given string:

package com.javahonk;

public class FindSubStringFromStringUsingBigO {

    public static void main(String[] args) {
        
        String value = "he hell hel hello world I am from heaven";      
        char valueArray[] = value.toCharArray();
        
        String subStringValue = "hello";
        char subStringArray[] = subStringValue.toCharArray();
        
        StringBuffer finalStringValue = new StringBuffer();
        
        int jIncrement = 0;
        
        //O(n) Brute Force algorithm 
        for (int i = 0; i < valueArray.length; i++) {
            char c = valueArray[i];
            
            for (int j=jIncrement; j < subStringArray.length;) {
                
                char s = subStringArray[j];
                if (c == s) {
                    System.out.print(s);
                    finalStringValue.append(s);
                    jIncrement++;
                    break;
                }else {
                    break;
                }
                
            }
            
        }
        
        if (subStringValue.equalsIgnoreCase(finalStringValue.toString())) {
            System.out.println("\nSub stirng found");
        }else {
            System.out.println("\nSub stirng not found");
        }
        
        
    }


}

Output: