Compilare: main.cpp: In function 'int back_track(int)': main.cpp:25:28: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses] 25 | if (poz & (1 << i) == 0) | ~~~~~~~~~^~~~ main.cpp: In function 'int main()': main.cpp:37:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation] 37 | for (int i = 1; i <= n; i++) | ^~~ main.cpp:39:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for' 39 | viz[0]=1; | ^~~