题解 | #判断回文#

public class Solution {
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * @param str string字符串 待判断的字符串
 * @return bool布尔型
 */
public boolean judge1(String str) {
    // write code here
    char[] array = str.toCharArray();
    int max_index = array.length - 1;
    if (max_index == 0) return true;

    for (int i = 0; i <= max_index; ++i) {
        if (array[i] != array[max_index - i]) return false;
        if (i == max_index - i || (max_index - i -i) == 1) break;
    }
    return true;
}

public boolean judge2(String str) {
    return new StringBuilder(str).reverse().toString().equals(str);
}

public boolean judge(String str) {
    int max_index = str.length() - 1;
    if (max_index == 0) return true;
    char[] array = str.toCharArray();
    int loop = max_index / 2;
    for (int i = 0; i < loop; ++i) {
        if (array[i] != array[max_index - i]) return false;
        if (i == max_index - i || (max_index - i -i) == 1) break;
    }
    return true;
}

public boolean judge3(String str) {
    int max_index = str.length() - 1;
    if (max_index == 0) return true;

    int loop = max_index / 2;
    for (int i = 0; i < loop; ++i) {
        if (str.charAt(i) != str.charAt(max_index - i)) return false;
        if (i == max_index - i || (max_index - i -i) == 1) break;
    }
    return true;
}
}