include<stdio.h> include<stdlib.h> include<string.h> defineucharunsignedchar defineuintunsignedint intpows(intx){ inty=1;for(;x!=0;x--)y=y*10;returny;} voiddisplay_result(doubleresult){ if(result<0){ printf("-");display_result(-result);} if(result>0){ doublei;intx;...