帮忙写几个C程序，用C语言编程，有急用！谢谢！

/*搞定了 你在TC下运行看 全部复制粘贴就行*/
#include
#include

struct student
{char no[5],name[10];
int score[4];
double average;
};

void fun1(void)
{int k=0;
char *p;
puts("enter a string:\n");
scanf("%s",p);
while(*p)
{if((*p)>=48&&(*p)<=57) /***p指向的字符为数字*/
if(k==0) {printf(" %c",(*p));k=1;}
else printf("%c",(*p));
else k=0;
p++;
}
}

void fun2(void)
{char week[7][10]={"Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"};
int n;
printf("enter a num(0 scanf("%d",&n);
if(n>0&&n<8)
printf("%s\n",week[n-1]);
else printf("num error!\n");
}

void readrec(int n,struct student *s)
{int sum=0,i,a;
int m=0;
printf("enter %d students rec\n",n);
for(i=0;i {sum=0;
printf("enter sno:");
scanf("%s",s->no);
printf("enter name:");
scanf("%s",s->name);
printf("enter four classes score(score1,score2,score3,score4):");
scanf("%d,%d,%d,%d", &s->score[0],&s->score[1],&s->score[2],&s->score[3]);
sum=s->score[0]+s->score[1]+s->score[2]+s->score[3];
s->average=sum/4.0;
s++;
}
}

void writerec(int n,struct student *s)
{int i;
printf("\n%d students rec:\nSno,name,four classes score and average:\n",n);
for(i=0;i {printf("%s,%s,%d,%d,%d,%d",s->no,s->name,s->score[0],s->score[1],s->score[2],s->score[3]);
printf("\taverage:%g\n",s->average);
s++;
}
}

void outch(void)
{char s[10],f;
int n;
char str[20];
char *p;
int len=0;
f='-';
n=10;
printf("enter the string:");
gets(str);
len=strlen(str);
p=str;
printf("enter command:");
gets(s);
if(strlen(s)<5) {f='-';n=10;}
else {f=s[4];n=s[5]-48;}
if(f=='-')
{if(len>=n) p=p+len-n;
puts(p);
}
else {for(;n>0;n--)
{printf("%c",*p);
p++;
}
}
}

void fun5()
{FILE *fp;
int n=10,i;
char str[99],ch='\n';
if( (fp= fopen( "data.txt", "w+" )) == NULL )
{
printf( "can't open file 'data.txt'\n" );
exit(0);
}
else printf("'data.txt'opened\n");
printf("enter %d strings\n",n);
for(;n>0;n--)
{gets(str);
fputs(str,fp);
fputc(ch,fp);
}
rewind(fp);
printf("show %d strings\n",n);
for(n=0;n<10;n++)
{i=0;
while(1)
{str[i]=fgetc(fp);
if(str[i]=='\n'||str[i]==EOF)
{str[i]='\0';break;}
else {printf("%c",str[i]);i++;}
}
puts("\n");
}
fclose(fp);
}

void main()
{struct student stu[5],*s;
s=stu;

fun1();
puts("\n");

fun2();
puts("\n");

readrec(5,stu);
puts("\n");
writerec(5,stu);
puts("\n");

getchar();
outch();
puts("\n");

fun5();
puts("\n");

getch();
}

1、
#include
void main()
{
char a;
printf("input the string\n");
for(;;)
{
scanf("%c",&a);
if(a=='\n')
break;
else if((a>='0')&&(a<='9'))
printf("%c",a);
}
printf("\n");
}
2、
#include
void main()
{
int i;
char a[7][10]={"Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"};
printf("input the choice num\n");
scanf("%d",&i);
printf("%s\n",a[i-1]);
}