Compilare: main.cpp: In function 'int main()': main.cpp:55:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 55 | for(int i=0;i<ctc.size()-1;i++) | ~^~~~~~~~~~~~~ main.cpp:32:13: warning: unused variable 'i' [-Wunused-variable] 32 | int n,m,i,a,b; | ^