/in/foo.cc: In function 'int main()':
/in/foo.cc:32:18: warning: format '%lld' expects argument of type 'long long int*', but argument 2 has type 'int*' [-Wformat=]
   scanf("%lld",&n);
                  ^
/in/foo.cc:33:51: warning: format '%lld' expects argument of type 'long long int*', but argument 2 has type 'int*' [-Wformat=]
   for (int i = 1; i <= n; ++ i) scanf("%lld",&b[i]) ,b[i]-=i; 
                                                   ^
/in/foo.cc:69:51: error: 'min' was not declared in this scope
         g[i] = min(g[i], g[from] + pre[k] + suf[k]); 
                                                   ^
/in/foo.cc:69:51: note: suggested alternative:
In file included from /usr/include/c++/6/algorithm:62:0,
                 from /in/foo.cc:9:
/usr/include/c++/6/bits/stl_algo.h:3453:5: note:   'std::min'
     min(initializer_list<_Tp> __l, _Compare __comp)
     ^~~