Compilare: main.cpp: In constructor 'mat::mat()': main.cpp:21:33: warning: 'void* memset(void*, int, size_t)' clearing an object of type 'struct std::pair<int, int>' with no trivial copy-assignment; use assignment instead [-Wclass-memaccess] 21 | memset(lin,0,sizeof(lin)); | ^ In file included from /usr/include/c++/10/bits/stl_algobase.h:64, from /usr/include/c++/10/bits/char_traits.h:39, from /usr/include/c++/10/ios:40, from /usr/include/c++/10/istream:38, from /usr/include/c++/10/sstream:38, from /usr/include/c++/10/complex:45, from /usr/include/c++/10/ccomplex:39, from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54, from main.cpp:1: /usr/include/c++/10/bits/stl_pair.h:211:12: note: 'struct std::pair<int, int>' declared here 211 | struct pair | ^~~~ main.cpp:22:33: warning: 'void* memset(void*, int, size_t)' clearing an object of type 'struct std::pair<int, int>' with no trivial copy-assignment; use assignment instead [-Wclass-memaccess] 22 | memset(col,0,sizeof(col)); | ^ In file included from /usr/include/c++/10/bits/stl_algobase.h:64, from /usr/include/c++/10/bits/char_traits.h:39, from /usr/include/c++/10/ios:40, from /usr/include/c++/10/istream:38, from /usr/include/c++/10/sstream:38, from /usr/include/c++/10/complex:45, from /usr/include/c++/10/ccomplex:39, from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:54, from main.cpp:1: /usr/include/c++/10/bits/stl_pair.h:211:12: note: 'struct std::pair<int, int>' declared here 211 | struct pair | ^~~~ main.cpp: In function 'void transforma(std::vector<std::pair<int, int> >&, std::vector<std::pair<int, int> >&)': main.cpp:110:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 110 | for(int i=0;i<a.size();i+=2) | ~^~~~~~~~~ main.cpp:123:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 123 | for(int i=0;i<a.size();i+=2) | ~^~~~~~~~~ main.cpp: In function 'void solve()': main.cpp:155:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<std::pair<int, int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 155 | for(int i=0;i<ca.size();i++) | ~^~~~~~~~~~