c语言程序设计题，急求！

#include<stdio.h>
#include<sting.h>
void main()
{
int s(int a);
int n;
char s[];
printf("请输入字符串和n的值");
scanf("%s,%c",n,s[]);
s(int n);
}
int s(int a);
for(i=1;i<=a;i++)
printf("%d");
printf("%s");}

#include "stdio.h"
#include <conio.h>
int main(){
int f(char s[],int n);
int n;
char s[99];
printf("Please input a char string:\n");
gets(s);
printf("Please input n:\n");
scanf("%d", &n);
if(!f(s, n))printf("Error!\n");
getch();
}
int f(char s[], int n){
int i = 0, length = 0;
char s_[n+1];
for(length = 0; s[length] != '\0'; length ++);
if(n > length) return 0;
for(i = 0; i < n; i ++){
s_[i] = s[i];
}