public static String longestPalindrome_solution2(String s) {
		int n = s.length();
		int longestBegin = 0;
		int maxLen = 1;
		boolean[][] table = new boolean[s.length()][s.length()];
		for (int i = 0; i < n; i++) {
			table[i][i] = true;
		}
		for (int i = 0; i < n - 1; i++) {
			if (s.charAt(i) == s.charAt(i + 1)) {
				table[i][i + 1] = true;
				longestBegin = i;
				maxLen = 2;
			}
		}
		for (int len = 3; len <= n; len++) {
			for (int i = 0; i < n - len + 1; i++) {
				int j = i + len - 1;
				if (s.charAt(i) == s.charAt(j) && table[i + 1][j - 1]) {
					table[i][j] = true;
					longestBegin = i;
					maxLen = len;
				}
			}
		}
		return s.substring(longestBegin, maxLen);
	}