Compilare: main.cpp: In function 'void display()': main.cpp:34:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::map<int, int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 34 | for(int j = 0; j < cols.size(); j++) | ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:88:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::map<int, int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 88 | for(int j = 0; j < cols.size(); j++) | ~~^~~~~~~~~~~~~ main.cpp:104:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::map<int, int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 104 | if(0 <= a && a < rows.size() && 0 <= b && b < cols.size() && !seen[a][b]) | ~~^~~~~~~~~~~~~ main.cpp:104:65: warning: comparison of integer expressions of different signedness: 'int' and 'std::map<int, int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 104 | if(0 <= a && a < rows.size() && 0 <= b && b < cols.size() && !seen[a][b]) | ~~^~~~~~~~~~~~~