C语言编程输出函数问题

每个题目都封装成函数了，代码如下，如有帮助，请采纳一下，谢谢。

#include <stdio.h>

//(1)题
int fun1(int n)
{
	return n * (n+1)* (n+2)/3;
}

//（2）题
char fun2()
{
	char ch;
	char ch2;
	printf("请输入一个字符：");
	scanf("%c%*c",&ch);
	ch2 = ch -1;
	printf("%c下一个字符是:%c\n",ch,ch2);
	return ch2;
}

//(2.2)
int fu22()
{
	char ch;
	int nmb;
	printf("请输入一个字符：");
	scanf("%c%*c",&ch);
	nmb = ch;
	printf("%c的整数：%d\n",ch,nmb);
	return nmb;
}

//(3)
void fun3( int n)
{
	int i,j;
	for (i = 1; i <= n; i++)
	{
		for (j = 1;j <= i; j++)
		{
			printf("*");
		}
		printf("\n");
	}
}
//（4）
void fun4()
{
	float pg, yl, xj, jz;
	float ss,st;
	printf("请输入苹果、压力、香蕉、橘子的重量：");
	scanf("%f %f %f %f",&pg,&yl,&xj,&jz);
	ss = 2.50 * pg + 1.80 * yl + 1.60 * xj + 2.00 *jz;//总钱数
	printf("应付%.2f元\n",ss);
	printf("请输入客户实付金额：");
	scanf("%f",&st);
	printf("应找钱数：%.2f\n",st - ss);
}

//(5)
unsigned int fun5(int x,int y)
{
	return x*x + y*y;
}
//(6)
float fun6(float r,float h)
{
	float v = 1.0/3.0 * 3.1415 * r* r * h; 
	printf("圆锥体积：%f\n",v);
	return v;
}
//(7)
void fun7(int *a,int *b,int* c)
{
	printf("交换前a=%d,b=%d,c=%d",*a,*b,*c);
	int tmp;
	tmp = (*a);
	(*a) = (*b);
	(*b) = (*c);
	(*c) = tmp;
	printf("交换后a=%d,b=%d,c=%d",*a,*b,*c);
}
//(8)
void fun8()
{
	int nmb,i = 0,t= 0;
	int a[3];
	printf("请输入三位整数：");
	scanf("%d",&nmb);
	while(nmb > 0)
	{
		a[i] = nmb % 10;
		i++;
		nmb = nmb/10;
	}
	for (t = 0; t < i; t++)
	{
		printf("%d",a[t]);
	}
	printf("\n");
}
void main()
{
	int a = 10 ,b = 7 ,c = 9;
	int res,n1,n3;
	int x,y;
	unsigned int ll;
	float r,h;
	printf("请输入题目1中n的值:");
	scanf("%d",&n1);
	res = fun1(n1);
	printf("计算结果=%d\n",res);

	fun2();

	printf("请输入题目3中需要显示的行数：");
	scanf("%d",&n3);
	fun3(n3);

	fun4();

	printf("题目5：请输入两个整数：");
	scanf("%d %d",&x,&y);
	printf("计算结果：%d\n",fun5(x,y));

	printf("题目6：请输入半径和高：");
	scanf("%f %f",&r,&h);
	printf("计算结果：%f\n",fun6(r,h));

	fun7(&a,&b,&c);

	fun8();
	return;
}