View Compilation Error

0_0_35096108_3324.cpp: In function 'int main()':
0_0_35096108_3324.cpp:11:1: error: expected initializer before 'for'
 for (i = 0; i != a; ++i){
 ^
0_0_35096108_3324.cpp:11:24: error: expected ';' before ')' token
 for (i = 0; i != a; ++i){
                        ^
0_0_35096108_3324.cpp:15:6: error: 'arr' was not declared in this scope
 sort(arr,arr+a);
      ^
0_0_35096108_3324.cpp:17:14: error: unable to deduce 'auto&&' from 'arr'
 for(auto &x: arr) {
              ^