Compilare: main.cpp: In function 'void dfs(int)': main.cpp:26:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | for(i=0;i<a[k].size();i++) | ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:69:44: warning: suggest parentheses around '-' inside '<<' [-Wparentheses] 69 | m[i][k]=min(m[i][k-1],m[i+(1<<k-1)][k-1]); | ~^~ main.cpp:70:44: warning: suggest parentheses around '-' inside '<<' [-Wparentheses] 70 | e[i][k]=min(e[i][k-1],e[i+(1<<k-1)][k-1]); | ~^~ main.cpp:50:11: warning: unused variable 'j' [-Wunused-variable] 50 | int i,j,k; | ^