chessboard.cpp: In function 'long long int fun(long long int)':
chessboard.cpp:21:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
21 | for (j=0;j<v[i].size();++j){
| ~^~~~~~~~~~~~
chessboard.cpp:23:26: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
23 | if (y%2 == 0 && c%2 == 1 || y%2 == 1 && c%2 == 0 )res--;
| ~~~~~~~~~^~~~~~~~~~~
chessboard.cpp:19:13: warning: unused variable 'ans' [-Wunused-variable]
19 | int i,j,ans=0,cnt=0,res=(n*n+1)/2,c=1;
| ^~~
chessboard.cpp: At global scope:
chessboard.cpp:34:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
34 | main(){
| ^
chessboard.cpp: In function 'int main()':
chessboard.cpp:53:15: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
53 | for (i=0;i<pr.size();++i){
| ~^~~~~~~~~~
chessboard.cpp:35:13: warning: unused variable 'j' [-Wunused-variable]
35 | int k,i,j;
| ^
chessboard.cpp:10:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
10 | #define scan2(a,b) scanf("%lld %lld",&a, &b);
| ~~~~~^~~~~~~~~~~~~~~~~~~~
chessboard.cpp:37:5: note: in expansion of macro 'scan2'
37 | scan2(n,k)
| ^~~~~
chessboard.cpp:10:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
10 | #define scan2(a,b) scanf("%lld %lld",&a, &b);
| ~~~~~^~~~~~~~~~~~~~~~~~~~
chessboard.cpp:41:9: note: in expansion of macro 'scan2'
41 | scan2(x1,y1)
| ^~~~~
chessboard.cpp:10:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
10 | #define scan2(a,b) scanf("%lld %lld",&a, &b);
| ~~~~~^~~~~~~~~~~~~~~~~~~~
chessboard.cpp:42:9: note: in expansion of macro 'scan2'
42 | scan2(x2,y2)
| ^~~~~