分段函数
x (x<1)
y= 2x-1 (1<=x<10)
3x-11 (x>=10)
输入x的值，输出y的值

#include <stdio.h>

int main()
{
	float x;
	float y;
	printf("请输入x的值：\n");
	scanf("%f",&x);
	if(x < 1){
		y=x;
	}else if(x >= 1 && x < 10){
		y=2*x-1;
	}else if(x >= 10){
		y=3*x-11;
	}
	printf("y = %f\n",y);
	
	return 0;
}