Compilare: main.cpp: In function 'void f(std::vector<int>&, int)': main.cpp:23:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); i ++) ~~^~~~~~~~~~ main.cpp:44:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); i ++) ~~^~~~~~~~~~ main.cpp:46:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v.size(); i ++) ~~^~~~~~~~~~ main.cpp: In function 'int u(int)': main.cpp:61:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v3.size(); i ++) ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:120:9: warning: unused variable 'cn' [-Wunused-variable] int cn = n; ^~