例53Pg5 maino X<I f int x, y scanf(%od, &x) 0 (x=0 if(x<0)y=-1: else if (x==0)y=0; (x>0) else v=l printf(x=%od, y=%dn",x, y) 程序1 程序2 程序3 if(x>=0) if(x>0)y=1: if(x!=0) if(x>=0) else y=0; if(x>0)y=1 if(x>0)y=1 Ise y=-I; eise else y=0;例5.3 Pg.95 -1 (x<0) y= 0 (x=0) 1 (x>0) main() { int x,y; scanf("%d",&x) if(x<0) y=-1; else if (x==0) y=0; else y=1; printf("x=%d,y=%d\n",x,y); } if(x>=0) if (x>0) y=1; else y=0; else y=-1; 程序1 y=0; if (x!=0) if (x>0) y=1; else y=-1; 程序2 y=-1; if(x>=0) if (x>0) y=1; else y=0; 程序3