Compilare: main.cpp: In function 'pii partition(std::vector<int>&, int, int)': main.cpp:37:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | for (int i = 0; i < lower.size(); i++) a[x++] = lower[i]; | ~~^~~~~~~~~~~~~~ main.cpp:41:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 41 | for (int i = 0; i < higher.size(); i++) a[x++] = higher[i]; | ~~^~~~~~~~~~~~~~~ main.cpp:35:20: warning: unused variable 'pos' [-Wunused-variable] 35 | int x = l, pos = l; | ^~~