明解C语言 入门版

从0开始的C语言学习：）
为了练习英语，我尽量用英文写代码和注释

练习2-1

显示出前者是后者的百分之几：

#include 

int main(void)
{
	int vx,vy;
	puts("请输入两个整数。");
	printf("整数a、整数b:n");   scanf_s("%d%d", &vx,&vy );
	printf("a是b的%d%%。n",100*vx/vy);
	
	return 0;
}

练习2-2

读取两个整数然后输出它们的和，积：

#include 

int main(void)
{
	int x, y;
	puts("please input two integer:");  scanf_s("%d%d", &x, &y);
	printf("sum=%d multiply=%d",x+y,x*y);
	return 0;
}

练习2-3

读出两个实数的值：

#include 

int main(void)
{
	double x;
	double y;

	puts("please put x,y:");
	printf("double x:");  scanf_s("%lf", &x);
	printf("double y:");  scanf_s("%lf", &y);

	printf("%fn%f",x,y);
	return 0;
}

练习2-4

对整型常量、浮点型常量、int型变量和double型变量进行乘除等各种运算：

#include 

int main(void)
{
	int n1, n2, n3, n4;
	double d1, d2, d3, d4;
	int x;
	double y;

	puts("please input x,y:");
	printf("int x:");  scanf_s("%d",&x);
	printf("double y:");  scanf_s("%lf",&y);
	printf("division x=%d multiply x=%dn", x / 2,x*2);
	printf("division y=%f multiply y=%fnn", y / 2.0,y*2.0);

	n1 = 5 / 2;
	n2 = 5.0 / 2.0;
	n3 = 5.0 / 2;
	n4 = 5 / 2.0;

	d1 = 5 / 2;
	d2 = 5.0 / 2.0;
	d3 = 5.0 / 2;
	d4 = 5 / 2.0;

	printf("n1=%dn", n1);
	printf("n2=%dn", n2);
	printf("n3=%dn", n3);
	printf("n4=%dnn", n4);

	printf("d1=%fn", d1 );
	printf("d2=%fn", d2);
	printf("d3=%fn", d3);
	printf("d4=%fn", d4);

	return 0;
}

练习2-5

计算前者是后者的百分之几，并用实数输出结果：

#include 

int main(void)
{
	int x, y;

	puts("please input two integer:");
	printf(" x:"); scanf_s("%d", &x);
	printf(" y:"); scanf_s("%d", &y);

	printf("x的值是y的%f %%。n",(double)(100*x/ y));

	return 0;
}

练习2-6

读取表示身高的整数值，显示出标准体重的实数值。标准体重根据公式（身高-100）*0.9进行计算，所得结果保留一位小数：

#include 

int main(void)
{
	double h;
	printf("please input your height;");  scanf_s("%lf", &h);
	printf("your standard weight is :%.1f kg", (h - 100) * 0.9);

	return 0;
}

练习3-1

输入两个整数，如果后者是前者的约数，则显示b是a的约数；如果不是，则显示b不是a的约数：

#include 

int main(void)
{
	int a, b;
	puts("please input two integer：");
	printf(" a：");  scanf_s("%d", &a);
	printf(" b：");  scanf_s("%d", &b);
	
	if (a % b)
		puts("b不是a的约数");
	    else
		puts("b是a的约数");
		
		return 0;
}

练习3-3

输入一个整数值，显示出它的绝对值：

#include 

int main(void)
{
	int x;
	printf("input an integer:");  scanf_s("%d", &x);

	if (x >= 0)
		printf("x的绝对值是%d",x);
		else
		printf("x的绝对值是%d",x=-x);

	return 0;
}

练习3-4

输入两个整数，显示它们之间的大小关系：

#include 

int main(void)
{
	int x,y;

	puts("input an integer:");
	printf(" x:");  scanf_s("%d", &x);
	printf(" y:");  scanf_s("%d", &y);

	if (x == y)
		puts("x equal y");
	else
		if (x > y)
			puts("x>y");
		else
			puts("x 
练习3-5
 
 
 
确认相等运算符和关系运算符的运算结果是1和0：
 
 
#include

int main(void)
{
    int a, b, c, d, e, f, x1, x2;

    puts("please input two integer:");
    printf(" x：");   scanf_s("%d", &x1);
    printf(" y：");   scanf_s("%d", &x2);

    a = (x1 == x2);
    b = (x1 != x2);
    c = (x1 <= x2);
    d = (x1 >= x2);
    e = (x1 > x2);
    f = (x1 < x2);
    printf("%d %d %d %d %d %d", a, b, c, d, e, f);

    return 0;
}
 
练习3-6
 
 
 
计算输入的三个整数中的最小值，并显示 ：
 
 
#include

int main(void)
{
	int a, b, c,min;
    printf("please input 3 integer:n");
    scanf_s("%d %d %d", &a, &b, &c);

	min = a;
	if (b < min) min = b;
	if (c < min) min = c;
		
	printf("the minimum one is %d.n", min);

	return 0;
}
 
练习3-7
 
 
 
计算输入的四个整数中的最大值并显示 ：
 
 
#include

int main(void)
{
	int a, b,c,d,max;

	printf("please input 4 integer:n");
	scanf_s("%d %d %d %d", &a, &b, &c, &d);
	
	max = a;
	if (b > max) max = b;
	if (c > max) max = c;
	if (d > max) max = d;

	printf("the biggest one is %d", max);

	return 0;
}
 
练习3-8
 
 
 
使用if语句计算输入的两个运算符的差值 ：
 
 
#include

int main(void)
{
	int a, b;

	printf("please input 2 integer:");
	scanf_s("%d%d", &a, &b);

	if (a > b)
		printf("the deviation is %d", a - b);
	else
		printf("the deviation is %d", b - a);

	return 0;
}
 
练习3-9
 
 
 
使用条件运算符，计算输入的三个整数中的最小值 ：
 
 
#include

int main(void)
{
	int a, b, c, min;
	printf("please input 3 integer:n");
	scanf_s("%d %d %d", &a, &b, &c);

	min = (b < a) ? b : a;
	min = (c < min) ? c : min;

	printf("the minimum one is %d.n", min);

	return 0;
}