View Compilation Error

0_0_32767932_25516.cpp: In function 'int main()':
0_0_32767932_25516.cpp:17:8: error: 'i' was not declared in this scope
   for (i = 1; i <= n; i++) {
        ^
0_0_32767932_25516.cpp:20:33: error: 'setiosflags' was not declared in this scope
   cout << setiosflags(ios::fixed) << setprecision(2) << (double(a[n]) / sum) * 100 << "%" << endl;
                                 ^
0_0_32767932_25516.cpp:20:52: error: 'setprecision' was not declared in this scope
   cout << setiosflags(ios::fixed) << setprecision(2) << (double(a[n]) / sum) * 100 << "%" << endl;
                                                    ^