c 언어 2차 작업

#include 

void splitfloat( float x, int *intpart, float *fracpart );

#include "stdio.h"
void delnum(char *s);
int main ()
{ char item[80];
gets(item);
delnum(item);
printf("%s
",item);
return 0;
}
void delnum(char *s)
{ int i=0,j=0;
while(*(s+i)!='\0')
    {if(!(*(s+i)<='9'&&*(s+i)>='0'))
    {*(s+j)=*(s+i);
    j++;}
    i++;}
    *(s+j)='\0';
} 

#include
int fun(char *str,char *substr);
int main()
{ char str[81]="asdasasdfgasdaszx67asdmklo",substr[4]="asd";
int n;
n=fun(str,substr);
printf("n=%d
",n);
return 0;
}
int fun(char *str,char *substr)
{
int i,j,k,num=0;
for(i=0;*(str+i);i++)
for(j=i,k=0;*(substr+k)==*(str+j);k++,j++)
if(*(substr+k+1)=='\0')
{
num++;
break;
}
return(num);
}

#include 
int fun(char *s,int num);
int main()
{
 char s[10];
 gets(s);
 fun(s,7);
 printf("%s",s);
 return 0;
 }
int fun(char *s,int num){
         int i,j,k,temp;
         for(i=1;i2;i++)
         {
             k=i;
             for(j=i+1;j1;j++)
             {
                 if(s[k]<s[j])
                 {
                     k=j;
                 }
             }
            if(k!=i)
            {
             temp=s[i];s[i]=s[k];s[k]=temp;
            }
        }
         return 0;
     }

#include 
int main()
{
  int N,grade,k,i=1;
  float average,max,min,sum=0.0;
  float maxy(float x,float y);
 float miny(float x,float y);
 scanf("%d",&N);
  for(k=0;k)
  {
    scanf("%d",&grade);
    sum=sum+grade;
   if (i==1)
   { max=grade;
    min=grade;
     i--;
   }
    max=maxy(max,grade);
    min=miny(min,grade);
  }
  average=sum/N;
  printf("average = %.2f
max = %.2f
min = %.2f",average,max,min);
  return 0;
}
float maxy(float x,float y)
  {
 float z;
 if(x>y)
 z=x;
 else
 z=y;
 return(z);
  }
 float miny(float x,float y)
  {
 float z;
 if(x<y)
 z=x;
 else
 z=y;
 return(z);
  }