View Compilation Error

0_0_16034210_29323.cpp:3:11: error: '::main' must return 'int'
 void main()
           ^
0_0_16034210_29323.cpp: In function 'int main()':
0_0_16034210_29323.cpp:8:60: error: 'sqrtf' was not declared in this scope
 fdist = sqrtf((x2 - x2) * (x2 - x1) + (y2 - y1) * (y2 - y1));
                                                            ^