View Compilation Error

0_0_13796800_21695.cpp:56:11: error: '::main' must return 'int'
 void main()
           ^
0_0_13796800_21695.cpp: In function 'int main()':
0_0_13796800_21695.cpp:75:8: error: 'i' was not declared in this scope
    for(i=1;i<=255;i++)
        ^
0_0_13796800_21695.cpp:82:8: error: 'i' was not declared in this scope
    for(i=0;i<nDNA-1;i++)
        ^