stones.cpp:20:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
20 | main(){
| ^
stones.cpp: In function 'int main()':
stones.cpp:21:11: warning: unused variable 'i' [-Wunused-variable]
21 | int n,i,l=0,r=0;
| ^
stones.cpp:11:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
11 | #define scan1(a) scanf("%lld",&a);
| ~~~~~^~~~~~~~~~~
stones.cpp:22:5: note: in expansion of macro 'scan1'
22 | scan1(n)
| ^~~~~
stones.cpp:12:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
12 | #define scan2(a,b) scanf("%lld %lld",&a, &b);
| ~~~~~^~~~~~~~~~~~~~~~~~~~
stones.cpp:25:9: note: in expansion of macro 'scan2'
25 | scan2(c,a)
| ^~~~~