View Compilation Error

0_0_30962006_23901.cpp:55:11: error: '::main' must return 'int'
 void main()
           ^
0_0_30962006_23901.cpp: In function 'int main()':
0_0_30962006_23901.cpp:73:5: error: 'i' was not declared in this scope
 for(i=1;i<=255;i++)
     ^
0_0_30962006_23901.cpp:80:5: error: 'i' was not declared in this scope
 for(i=0;i<nDNA-1;i++)
     ^