*[topcoder]LongWordsDiv2

http://community.topcoder.com/stat?c=problem_statement&pm=13147

此题关键在于发现ABAB的组合最多有26*26种，可以穷举，然后用判断子序列~

#include <vector>

#include <iostream>

using namespace std;



class LongWordsDiv2 {

public:

    string find(string word) {

    	for (int i = 0; i < word.size() - 1; i++) {

    		if (word[i] == word[i+1])

    			return "Dislikes";

    	}

        for (char x = 'A'; x <= 'Z'; x++) {

            for (char y = 'A'; y <= 'Z'; y++) {

                string tmp = "";

                tmp += x;

                tmp += y;

                tmp += x;

                tmp += y;

                if (subSeq(word, tmp))

                    return "Dislikes";

            }

        }

        return "Likes";

    }

    

    bool subSeq(string a, string b) {

        int i = 0;

        int j = 0;

        while (i < a.size() && j < b.size()) {

            if (a[i] == b[j])

                j++;

            i++;

        }

        return (j == b.size());

    }

};