求“天干地支”算法

已知天干地支，求对应的数值。拒绝查表法，最好有Java代码。
谢谢

如，
已知 甲子 求得结果 1
已知 壬辰 求得结果 29

我写了个，[code="java"]

import java.util.HashMap;

public class ChineseCalendar {
private final static HashMap Heavenly_Stems = new HashMap();
private final static HashMap Earthly_Branches = new HashMap();
static {
Heavenly_Stems.put('甲', 1);
Heavenly_Stems.put('乙', 2);
Heavenly_Stems.put('丙', 3);
Heavenly_Stems.put('丁', 4);
Heavenly_Stems.put('戊', 5);
Heavenly_Stems.put('己', 6);
Heavenly_Stems.put('庚', 7);
Heavenly_Stems.put('辛', 8);
Heavenly_Stems.put('壬', 9);
Heavenly_Stems.put('癸', 10);

    Earthly_Branches.put('子', 1);
    Earthly_Branches.put('丑', 2);
    Earthly_Branches.put('寅', 3);
    Earthly_Branches.put('卯', 4);
    Earthly_Branches.put('辰', 5);
    Earthly_Branches.put('巳', 6);
    Earthly_Branches.put('午', 7);
    Earthly_Branches.put('未', 8);
    Earthly_Branches.put('申', 9);
    Earthly_Branches.put('酉', 10);
    Earthly_Branches.put('戌', 11);
    Earthly_Branches.put('亥', 12);
}

public static int getCode(String name) {
    int n = name.length();
    if (n < 2)
        throw new IllegalArgumentException("Unknown name: " + name);

    char h = name.charAt(0);
    Integer hCode = Heavenly_Stems.get(h);
    if (hCode == null)
        throw new IllegalArgumentException("Unknown name: " + name);
    char e = name.charAt(1);
    Integer eCode = Earthly_Branches.get(e);
    if (eCode == null)
        throw new IllegalArgumentException("Unknown name: " + name);
    hCode%=10;
    eCode%=12;
    for (int c = 1; c <= 60; c++) {
        if (c % 10 == hCode && c % 12 == eCode)
            return c;
    }
    throw new IllegalArgumentException("Unknown name: " + name);
}

public static void main(String[] args) {
    System.out.println(getCode("甲子"));
    System.out.println(getCode("壬辰"));
    System.out.println(getCode("癸酉"));
    System.out.println(getCode("癸亥"));

}

}

[/code]

其实用查表法是最好的