第二部分（一）：求实数的绝对值

2021/11/26

#include<stdio.h>
main()
{
	float a, b;
	printf("input a real number,system will return its absolute value:\n");
	while (scanf_s("%f", &b) != EOF)
	{
		if (b < 0)
			b = -b;
		printf("%f\n", b);
	}
}