编译错误：cin在此作用域中未定义

#include <istream>
#include <ostream>
#include <fstream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <string>
#include <cstring>
#include <vector>
#include <map>
#define int long long
using namespace std;
signed main(){
    int n,c=1;
    cin>>n;
    char a[n+1];c[0]=' ';
    for(int i=1;i<=n;i++){
        cin>>c[i];
        if(c[i]==c[i-1]) ++c;
    }
    cout<<c;
}