5_4.cpp

C程序参考,简单易懂,是初学者不可少的参考资料

#include<stdio.h>
#include<math.h>
main()
 {
     float x,y;
     printf("Please enter a float x:\n");
     scanf("%f",&x);
     if(x>=0)
         y=x*x-2;
     else
         y=4-x;
     printf("x=%f\ty=%f\n",x,y);
 }