关于c语言 编写程序

#include<stdio.h>
void main()
{
int M(int x,int y);
int N(int x,int y);
int a,b,max,min;
printf("**********Please input 2 numbers**********\n");
scanf("%d%d",&a,&b);
max = M(a,b);
min = N(a,b);
printf("Do you want to know what's the common divisor is?\n**********It is %d**********\nDo you want to know what's the common multiple is?\n**********It is %d**********\n",a,b);
}

int M(int x,int y)
{
int r,z;
if(x < y)
{
r = y;
y = x;
x = r;
}
r = x % y;
while(r != 0)
{
x = y;
y = r;
r = x % y;
}
if(r == 0)
{
z = y;
}
return z;
}

int N(int x,int y)
{
int i,r,t,x1,y1;
x1 = x;
y1 = y;
if(x < y)
{
r = y;
y = x;
x = r;
}
r = x % y;
while(r !=