ho_t2.cpp:29:5: error: 'int jn' redeclared as different kind of symbol
int jn, on, in;
^~
In file included from /usr/include/features.h:367:0,
from /usr/include/x86_64-linux-gnu/c++/7/bits/os_defines.h:39,
from /usr/include/x86_64-linux-gnu/c++/7/bits/c++config.h:533,
from /usr/include/c++/7/cassert:43,
from /usr/include/x86_64-linux-gnu/c++/7/bits/stdc++.h:33,
from ho_t2.cpp:1:
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:249:1: note: previous declaration 'double jn(int, double)'
__MATHCALL (jn,, (int, _Mdouble_));
^
ho_t2.cpp: In function 'int main()':
ho_t2.cpp:38:11: warning: ISO C++ forbids incrementing a pointer of type 'double (*)(int, double) noexcept' [-Wpointer-arith]
a[jn++] = i;
^~
ho_t2.cpp:38:11: error: lvalue required as increment operand
ho_t2.cpp:45:15: warning: pointer to a function used in arithmetic [-Wpointer-arith]
FOR(i, 0, jn-1) {
~~^~
ho_t2.cpp:24:46: note: in definition of macro 'FOR'
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
^
ho_t2.cpp:24:47: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
^
ho_t2.cpp:45:3: note: in expansion of macro 'FOR'
FOR(i, 0, jn-1) {
^~~
ho_t2.cpp:46:22: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
if (i + k - 1 >= jn) break;
^~