请各位看看这是那里错了呢

···

#include <iostream>
using namespace std;
#include <string>
int main()
{
    int a;
    cin>>a;
    int s[a];
    gets(s);
    int b=a;

int n[b]

    for (int i=1;<=a;i++)
    {
        if(s[b]==z)
            n[b]=a;
        else 
            s[b]=s[b+1];
        b=b-1;
    }
    cout<<s;
}
···