Compilare: main.cpp: In function 'bool compare(std::vector<int>, std::vector<int>)': main.cpp:24:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < a.size ( ); i++ ){ ~~^~~~~~~~~~~~ main.cpp: In function 'std::vector<int> operator+(std::vector<int>, int)': main.cpp:42:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while ( r != 0 && i < x.size ( ) ){ ~~^~~~~~~~~~~~ main.cpp: In function 'std::vector<int> operator-(std::vector<int>, std::vector<int>)': main.cpp:58:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0; i < x.size ( ); i++ ){ ~~^~~~~~~~~~~~ main.cpp:59:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ( i < y.size ( ) ){ ~~^~~~~~~~~~~~ main.cpp: In function 'std::vector<int> operator/(std::vector<int>, int)': main.cpp:76:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0; i < x.size ( ); i++ ){ ~~^~~~~~~~~~~~ main.cpp: In function 'void afisare(std::vector<int>)': main.cpp:111:13: warning: unused variable 'num' [-Wunused-variable] int num = a[i]; ^~~