View Compilation Error

0_0_18865815_10407.cpp:18:1: error: 'byte' does not name a type
 byte bitcount[4]={0,1,1,2};
 ^
0_0_18865815_10407.cpp: In function 'int main()':
0_0_18865815_10407.cpp:31:29: error: 'bitcount' was not declared in this scope
         for(int i=0;i<=3 && bitcount[i]<=s[1];i++)
                             ^
0_0_18865815_10407.cpp:40:33: error: 'bitcount' was not declared in this scope
             for(int x=0;x<=3 && bitcount[x]<=s[i];x++)
                                 ^