Compilare: main.cpp: In function 'int main()': main.cpp:23:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 23 | for ( i = 0; i < a.size(); i ++ ) { | ~~^~~~~~~~~~ main.cpp:24:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 24 | for ( int j = i + 1; j < a.size(); j ++ ) | ~~^~~~~~~~~~ main.cpp:28:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | for ( i = 0; i < r.size(); i ++ ) { | ~~^~~~~~~~~~ main.cpp:29:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 29 | for ( int j = i + 1; j < r.size(); j ++ ) | ~~^~~~~~~~~~ main.cpp:42:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 42 | for ( i = 0; i < a.size(); i ++ ) { | ~~^~~~~~~~~~ main.cpp:43:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 43 | for ( int j = i + 1; j < a.size(); j ++ ) | ~~^~~~~~~~~~