View Compilation Error

0_0_22737963_24740.cpp: In function 'int main()':
0_0_22737963_24740.cpp:33:27: error: invalid types 'double[int]' for array subscript
                 mid.x=(a[i].x+a[j].x)/2;
                           ^
0_0_22737963_24740.cpp:33:34: error: invalid types 'double[int]' for array subscript
                 mid.x=(a[i].x+a[j].x)/2;
                                  ^
0_0_22737963_24740.cpp:34:27: error: invalid types 'double[int]' for array subscript
                 mid.y=(a[i].y+a[j].y)/2;
                           ^
0_0_22737963_24740.cpp:34:34: error: invalid types 'double[int]' for array subscript
                 mid.y=(a[i].y+a[j].y)/2;
                                  ^
0_0_22737963_24740.cpp:38:17: error: expected primary-expression before '}' token
                 }
                 ^
0_0_22737963_24740.cpp:38:17: error: expected ',' or ';' before '}' token