计算派的代码，可以随便调整小数点后的精确值 -calculated to send the code can easily adjust the precision decimal value

输入1-13中的四个数，输入要计算的值（24点游戏就输入24），计算机穷举法给出计算公式-Enter the four numbers 1-13, enter the values ​ ​ to be calculated (24-point game on the importation of 24), the computer gives exhaustive formula