对于符号三角形问题，符号三角形的第一行有n个符号。符号可以为“＋”或“－”，以下每一行的符号由上行得到，2个同号下面都是“+”，2个异号下面都是“－”。-Problem for triangle symbols, symbols of the first line of the triangle has n symbols. Symbols for "+"　or "-" , the following symbols for each line obtained by the uplink, with the No. 2 the following are the "+" , No. 2 The following are different "-."