View Compilation Error

0_0_15956053_14234.cpp:2:11: error: '::main' must return 'int'
 void main()
           ^
0_0_15956053_14234.cpp: In function 'int main()':
0_0_15956053_14234.cpp:12:25: error: 'fabs' was not declared in this scope
             if(fabs(a[j])>fabs(a[i]))
                         ^