Compilare: main.cpp: In function 'void build(int, int, int)': main.cpp:41:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 41 | while(i < a[lc].size() && j < a[rc].size()) | ~~^~~~~~~~~~~~~~ main.cpp:41:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 41 | while(i < a[lc].size() && j < a[rc].size()) | ~~^~~~~~~~~~~~~~ main.cpp:43:13: warning: unused variable 'x' [-Wunused-variable] 43 | int x = a[lc][i]; | ^ main.cpp:44:13: warning: unused variable 'y' [-Wunused-variable] 44 | int y = a[rc][j]; | ^ main.cpp:50:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 50 | while(i<a[lc].size()) | ~^~~~~~~~~~~~~ main.cpp:52:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 52 | while(j<a[rc].size()) | ~^~~~~~~~~~~~~ main.cpp: In function 'int cb(int)': main.cpp:99:1: warning: control reaches end of non-void function [-Wreturn-type] 99 | } | ^