View Compilation Error

0_0_22083095_20268.cpp: In function 'int main()':
0_0_22083095_20268.cpp:19:3: error: 'nega_count' was not declared in this scope
   nega_count = 0;
   ^
0_0_22083095_20268.cpp:28:31: error: 'n' was not declared in this scope
    cout<<0<<" "<<a[0]<<" "<<a[n - 1]<<endl;
                               ^