Algorithm exercise: Find the longest repeating substring of a string (Java implementation)

1. Find the longest repeating substring of a string

For example: AAAAAAAAABBBBCCCAAASSSCVVV the longest repeating substring inside this is AAAAAAAAA

Algorithmic thinking: Algorithmic Time complexity (O (n))

1. Turn this string into a char array first;

2. Iterate over this char array

3. Compares the characters of i-1 and I in a char array, if not equal, intercepts the string length, compares it, and replaces it if it is longer than the existing length, or does nothing

Algorithm implementation: (Java Implementation)

    private static string Resubstr (String str) {        /**         * Set Variable         * Start: Start         * End: End         * Maxstart: Oldest string start position         * Maxend: Oldest string End position         */        int start=0,end=1,maxstart=0,maxend=1;        char[] chars = Str.tochararray ();        for (int i = 1; i < chars.length; i++) {            //To determine if not equal, the length of the calculator if            (Chars[i-1]!=chars[i]) {
Sets the end position of its repeating substring                end=i;                substring length                int len = End-start;                The substring length is greater than the existing maximum substring length                if (Len > (Maxend-maxstart)) {                    //is assigned                    Maxstart = start;                    Maxend = end;                }                Start intercept position for end position                start = end;}        }        Intercept string        return str.substring (maxstart,maxend);    }

　　

Algorithm exercise: Find the longest repeating substring of a string (Java implementation)