给定4个整数，其中每个数字只能使用一次；任意使用 + - * / ( ) ，构造出一个表达式，使得最终结果为24，这就是常见的算24点的游戏。这方面的程序很多，一般都是穷举求解。本程序利用递归算计计算24点。-Given four integers, each number can only be used once　any+-*/(), to construct an expression that the end result is 24, which is a common operator a 24-point game. Many procedures in this respect, are generally exhaustive solution. This procedure using recursive calculation calculation of 24 points.