c语言练习题

在键盘上输入三个数，求他们的最大值

1.
int Max_Int(int a,int b)
{
	return a > b ? a : b;
}

int main()
{
	int a = 0, b = 0, c = 0;
	scanf_s("%d%d%d", &a, &b, &c);
	int max = 0;
	max = Max_Int(Max_Int(a, b), c);//函数的递归，先将a,b的最大值比较出来，把值给一个临时的变量，再将变量和c进行比较
	printf("max=%dn", max);
	return 0;
}


2.
int main()
{
	int a = 0, b = 0, c = 0;
	scanf_s("%d%d%d", &a, &b, &c);
	int max = 0;
	max = a > b ? a : b;
	max = max > c ? max : c;
	printf("max=%dn", max);
	return 0;
}



3.
int main()
{
	int a = 0, b = 0, c = 0;
	scanf_s("%d%d%d", &a, &b, &c);
	int max = 0;
	if (a > b && a > c)
	{
		max = a;
	}
	else if (b > a && b > c)
	{
		max = b;
	}
	else
		max = c;
	printf("max=%dn", max);
	return 0;
}

在键盘上输入三个数求他们中间的那个数

void swap(int* a, int* b)
{
	int temp = 0;//int *temp=NULL;只是一个空指针，没有地址，所以指针指向随机值，不能使用空指针在这
	temp = *a;
	*a = *b;
	*b = temp;
}

int Mid_Int(int x, int y, int z)
{
	if (x > y)
	{
		swap(&x, &y);
	}
	if (y > z)
	{
		swap(&y, &z);
	}
	if (x > y)
	{
		swap(&x, &y);
	}
	return y;
}

int main()
{
	int a = 0, b = 0, c = 0;
	scanf_s("%d%d%d", &a, &b, &c);
	int mid = 0;
	mid = Mid_Int(a, b, c);
	printf("mid=%dn", mid);
	return 0;
}


int Mid_Int(int a, int b, int c)
{
	int temp = 0;
	if (a > b)
	{
		temp = a;
		a = b;
		b = temp;
	}
	if (b > c)
	{
		temp = c;
		c = b;
		b = temp;
	}
	if (a > b)
	{
		temp = a;
		a=b;
		b = temp;
	}
	return b;
}

int main()
{
	int a = 0, b = 0, c = 0;
	scanf_s("%d%d%d", &a, &b, &c);
	int mid = 0;
	mid = Mid_Int(a, b, c);
	printf("mid=%dn", mid);
	return 0;

}

在键盘上输入一行或多行字符串，统计他们其中数字，大小写字母，控制字符，以及其他字符

int main()
{
	char ch = '';
	int consum = 0, digsum = 0, capsum = 0, smasum = 0, othsum = 0;
	while (ch = getchar(), ch != 'n')
	{
		if (iscntrl(ch))
		{ 
			consum += 1; 
		}
		else if (isdigit(ch)) 
		{ 
			digsum += 1; 
		}
		else if (isupper(ch))
		{ 
			capsum += 1; 
		}
		else if(islower(ch)) 
		{
			smasum += 1; 
		}
		else 
		{ 
			othsum += 1; 
		}

	}
	    printf("consum: %d n", consum);
		printf("digsum: %d n", digsum);
		printf("capsum: %d n", capsum);
		printf("smasum: %d n", smasum);
		printf("othsum: %d n", othsum);
	    return 0;
}