Compilare: main.cpp: In function 'int main()': main.cpp:100:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<group>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 100 | while (j < a[i].size()) | ~~^~~~~~~~~~~~~ main.cpp:105:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<group>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 105 | while (j < a[i].size() && a[i][j].val == a[i][k].val) | ~~^~~~~~~~~~~~~ main.cpp:117:28: warning: comparison of integer expressions of different signedness: 'std::vector<group>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 117 | while (a[i].size() > k) | ~~~~~~~~~~~~^~~ main.cpp:122:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<group>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 122 | for (int j = 0; j < a[i].size(); j++) | ~~^~~~~~~~~~~~~ main.cpp:26:18: warning: unused variable 'y' [-Wunused-variable] 26 | long long x, y; | ^