A simple and faster iterative method

  • 0

    If you are not able to figure out how to proceed, look at the string. If you start with "1" and look from left to right, you would realize that you would start counting a number left to right till : 1. either another number shows up , or 2. the string ends. Use this logic to read say "211". You first read 2 with a count of 1 and then read 2 1s. Here is the code:

        public String countAndSay(int n) {
                “1211” -> "111221
            String s = "1";
            for(int i=2;i<=n;i++) {
                StringBuilder builder = new StringBuilder();
                int j=0;
                while(j<s.length()) {
                    int count=1;
                    char c = s.charAt(j);
                    while(j+1<s.length() && s.charAt(j+1)==c) {
                s = builder.toString();
            return s;

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