Compilare: main.cpp: In function 'void dfs(int, int, int)': main.cpp:31:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | for (i = 0; i < a[x].size(); i++) { | ~~^~~~~~~~~~~~~ main.cpp: In function 'void dfs2(int, int, int, int)': main.cpp:44:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 44 | for (int i = 0; i < a[x].size(); i++) { | ~~^~~~~~~~~~~~~ main.cpp:41:9: warning: unused variable 'i' [-Wunused-variable] 41 | int i; | ^ main.cpp: In function 'void solve()': main.cpp:54:12: warning: unused variable 'j' [-Wunused-variable] 54 | int i, j, k; | ^ main.cpp:54:15: warning: unused variable 'k' [-Wunused-variable] 54 | int i, j, k; | ^