Compilare: user.cpp: In function ‘int main()’: user.cpp:31:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0;k<a[j].size();k++) ^ user.cpp:42:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[0].size();i++) sol=min(sol,c[1<<n-1][a[0][i]]+cost[0][a[0][i]]); ^ user.cpp:42:50: warning: suggest parentheses around ‘-’ inside ‘<<’ [-Wparentheses] for(i=0;i<a[0].size();i++) sol=min(sol,c[1<<n-1][a[0][i]]+cost[0][a[0][i]]); ^