Compilare: user.cpp: In function ‘int main()’: user.cpp:20:2: warning: this ‘for’ clause does not guard... [-Wmisleading-indentation] for(it=a.begin();it!=a.end();it++) ^~~ user.cpp:23:5: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the ‘for’ return 0; ^~~~~~ user.cpp:10:10: warning: unused variable ‘j’ [-Wunused-variable] {int n,i,j,x; ^