Compilare: main.cpp: In function 'int floodfill(int)': main.cpp:24:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 24 | for (j = 0; r == 0 && j < v[i].size(); j++) { | ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:63:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 63 | for (i = 0; r == 0 && i < v.size(); i++) { | ~~^~~~~~~~~~ main.cpp:38:10: warning: unused variable 'j' [-Wunused-variable] 38 | int n, j, m, i, a, b, r; | ^