直。

Paste_Image.png

#include<stdio.h>
#include<string.h>
#define N 255
void fun(char [],char []);
int main()
{
    char a[N],b[N];
    gets(a);
    fun(a,b);
    puts(b);
    return 0;
}
void fun(char a[],char b[])
{
    int i=0,j;
    for(j=0;a[j]!='\0';j++);
    j--;
    for(;j>=0;j--)
        b[i++]=a[j];
    b[i]='\0';
}

Paste_Image.png

#include<stdio.h>
#define N 20
int fun(int k);
int main(void)
{
    char a[N];
    int i,j,n,x,k=1,sum=1;
    scanf("%d\n",&n);
    gets(a);
    for(i=0;i<n;i++)
    {
        for(j=i+1;j<n;j++)
        {
            if(a[i]==a[j])
            k++;}
            x=fun(k);
            k=1;
            sum*=x;
    }
    printf("%d",fun(n)/sum);
    return 0;
}
int fun(int k)
{int x=1,i;
for(i=1;i<=k;i++)
x*=i;
return x;}```
3.
![Paste_Image.png](http://upload-images.jianshu.io/upload_images/1694063-cccbf05ad905ccd8.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
```cpp
#include<stdio.h>
#include<string.h>
#define N 255
void fun(char [],char []);
int change(char [],char []);
int main()
{
    char a[N],b[N];
    gets(a);
    fun(a,b);
    if(change(a,b)==0)
        printf("Y");
    else
        printf("N");
    return 0;
}
void fun(char a[],char b[])
{
    int i=0,j;
    for(j=0;a[j]!='\0';j++);
    j--;
    for(;j>=0;j--)
        b[i++]=a[j];
    b[i]='\0';
}
int change(char a[],char b[])
{
    int i=0;
    for(i=0;a[i]==b[i];i++)
        if(a[i]=='\0')
            return 0;
    return 1;
}```
4.
![Paste_Image.png](http://upload-images.jianshu.io/upload_images/1694063-81398b6f35ae4b76.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
```cpp
#include<stdio.h>
#include<string.h>
#define N 100
void fun(char [],char []);
int main()
{
    char a[N],b[N];
    gets(a);
    fun(a,b);
    puts(b);
}
void fun(char a[],char b[])
{
    int i=0,j;
    for(j=0;a[j]!='\0';j++);
    j--;
    for(;j>=0;j--)
        b[i++]=a[j];
    b[i]='\0';
}

Paste_Image.png

#include<stdio.h>
#include<string.h>
#define N 100
void fun(char [],char []);
int main()
{
    char a[N],b[N];
    gets(a);
    gets(b);
    fun(a,b);
    puts(a);
    return 0;
}
void fun(char a[],char b[])
{
    int i,j;
    for(j=0;a[j]!='\0';j++);
    for(i=0;b[i]!='\0';i++)
    {
        a[j]=b[i];
        j++;
    }
    a[j]='\0';
}```
6.
![Paste_Image.png](http://upload-images.jianshu.io/upload_images/1694063-34fc596fe432ef47.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
```cpp
#include<stdio.h>
#include<string.h>
#include<math.h>
#define N 100
int fun(char []);
int main()
{
    char a[N];
    gets(a);
    printf("%d",fun(a));
    return 0;
}
int fun(char a[])
{
    int i,j,sum=0;
    for(j=0;a[j]!='\0';j++);
    for(i=0;a[i]!='\0';i++)
    {
        sum+=(a[i]-48)*pow(8,--j);
    }
    return sum;
}```
7.
![Paste_Image.png](http://upload-images.jianshu.io/upload_images/1694063-6f2509d812abd1b7.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
```cpp
#include<stdio.h>
void fun(char *p)
{
    int i,j=0;
    char a[1024];
    for(i=0;p[i]!='\0';i++)
        if(p[i]!='*')
            a[j++]=p[i];
        a[j]='\0';
        for(i=0;a[i]!='\0';i++)
            p[i]=a[i];
        p[i]='\0';
}
int main()
{
    char b[1024];
    while(gets(b)!=NULL)
    {
         fun(b);
        printf("%s\n",b);

    }

return 1;

}```
8.
![Paste_Image.png](http://upload-images.jianshu.io/upload_images/1694063-e8980d278aa9986d.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
```cpp
#include<stdio.h>
void fun(char [],char []);
#define N 256
int main()
{
    char a[N],b[N];
    int n=0,k=0,i;
    gets(a);
    gets(b);
    for(i=0;a[i]!='\0';i++)
        n++;
    for(i=0;b[i]!='\0';i++)
        k++;
    if(n==k)
        printf("error");
    else if(n>k)
    {
        for(i=0;i<k;i++)
            a[i]=b[i];
        puts(a);
    }
    else if(n<k)
    {
        for(i=0;i<n;i++)
            b[i]=a[i];
        puts(b);
    }
    return 0;
}```