foo.cpp: In function 'int main()':
foo.cpp:9:18: error: expected ':' before ')' token
 for(i=1;i<=10?i++)
                  ^
foo.cpp:9:18: error: expected primary-expression before ')' token
foo.cpp:9:18: error: expected ';' before ')' token
foo.cpp:10:14: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[500]' [-Wformat=]
 scanf("%s",&a);
              ^