Compilare: main.cpp: In function 'int Back(int, std::string)': main.cpp:85:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 85 | for(int i=0; i<c.size(); i++) | ~^~~~~~~~~ main.cpp:140:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 140 | for(int i=0; i<c.size(); i++) | ~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:262:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 262 | for(int i=0; i<c.size(); i++) | ~^~~~~~~~~ main.cpp:269:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 269 | for(int i=0; i<c.size(); i++) | ~^~~~~~~~~ main.cpp:271:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 271 | for(int j=i+1; j<c.size(); j++) | ~^~~~~~~~~ main.cpp:280:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 280 | for(int i=0; i<c.size(); i++) | ~^~~~~~~~~