View Compilation Error

0_0_38228690_11732.cpp: In function 'int main()':
0_0_38228690_11732.cpp:14:32: error: invalid conversion from 'int' to 'const char*' [-fpermissive]
         for(int i=0; i<strlen(b); i++){
                                ^
In file included from 0_0_38228690_11732.cpp:3:0:
GCC4.9.2/x86_64-w64-mingw32/include/string.h:54:18: note: initializing argument 1 of 'size_t strlen(const char*)'
   size_t __cdecl strlen(const char *_Str);
                  ^