View Compilation Error

0_0_22756530_31663.cpp: In function 'int main()':
0_0_22756530_31663.cpp:10:15: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
         if(a>='A'&&a<='Z') printf("%d\n",a[0]+b-64);
               ^
0_0_22756530_31663.cpp:10:23: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
         if(a>='A'&&a<='Z') printf("%d\n",a[0]+b-64);
                       ^
0_0_22756530_31663.cpp:11:15: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
         if(a>='a'&&a<='z') printf("%d\n",-a[0]+b+96);
               ^
0_0_22756530_31663.cpp:11:23: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
         if(a>='a'&&a<='z') printf("%d\n",-a[0]+b+96);
                       ^