View Compilation Error

0_0_34900874_10380.cpp: In function 'int main()':
0_0_34900874_10380.cpp:17:9: error: 'i' was not declared in this scope
    if(a[i]==(0,1,4,5,8,9,12,13,16,17,20,21,24))
         ^
0_0_34900874_10380.cpp:22:15: error: expected primary-expression before '{' token
    else(a[i]=={3,6,7,10,11,14,15,18,19,22,23,26,27})
               ^
0_0_34900874_10380.cpp:22:15: error: expected ')' before '{' token