假设内存单元中有三个字a、b和c，编写一个程序，它可判断它们能否构成一个三角形，若能，显示“Y”，否则，显示“N”；-Suppose there are three words in the memory cell a, b and c, write a program that can determine whether they can form a triangle if we can show that " Y" , otherwise display " N"