Compilare: main.cpp: In function 'void Add(int)': main.cpp:15:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 15 | for (i = 0; i < a[r].size(); i++) | ~~^~~~~~~~~~~~~ main.cpp: In function 'void Delete(int)': main.cpp:24:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 24 | for (i = 0; i < a[r].size(); i++) | ~~^~~~~~~~~~~~~ main.cpp: In function 'int Find(int)': main.cpp:34:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 34 | for (i = 0; i < a[r].size(); i++) | ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:41:9: warning: unused variable 'i' [-Wunused-variable] 41 | int i, x; | ^