实验4电

#include<stdio.h>
int main(void)
{
    double x,y;
    
    printf("Enter x:");
    scanf("%lf",&x);
    if(x<0){
        printf("输入错误");
    }
    
    else if(x<50){
        y=0.53*x;
    }
    
    else(x>50);{
        y=0.58*x;
    }
    
    printf("y=%lf
",y);

    return 0;
}