X、Y、(X-Y)、Z四个数;X>=0,正整数;Y>=0,正整数;1>=z>=-1。case
when x=y then z=0;
when y=0 then z=1;
when x=0 then z=-1;
when x>y then z=(x-y)/y ; =右边用什么函数可以让Z的值满足Y越小,Z越大且 1>z>0 ?
when x<y then z=(x-y)/x ; =右边用什么函数可以让Z的值满足X越小,Z越小且 0>z>-1 ?
end case;
when x=y then z=0;
when y=0 then z=1;
when x=0 then z=-1;
when x>y then z=(x-y)/y ; =右边用什么函数可以让Z的值满足Y越小,Z越大且 1>z>0 ?
when x<y then z=(x-y)/x ; =右边用什么函数可以让Z的值满足X越小,Z越小且 0>z>-1 ?
end case;
when x<y then z=(x-y)/x ; =右边用什么函数可以让Z的值满足X越小,Z越小且 0>z>-1 ?z和x也有关系 没办法单纯按照y来确定z
or (y=0 and z=1)
or (x=0 and z=-1)
or (x>y and z<1 and z>0)
or (x<y and z<0 and z>-1)
表达式为:
z=(x/(x+y)-0.5)*2
详见http://topic.csdn.net/u/20120626/15/9ef5c091-c625-498b-a8dd-357f0f52d195.html