Compilare: main.cpp: In function 'int valid(int)': main.cpp:16:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation] for(int i=1;i<k;i++) if(stiva[i]==stiva[k]) return 0; return 1; ^~~ main.cpp:16:59: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for' for(int i=1;i<k;i++) if(stiva[i]==stiva[k]) return 0; return 1; ^~~~~~ main.cpp: In function 'void bt(int)': main.cpp:23:11: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if(valid(k)==1) ^ main.cpp: In function 'int factorial(int)': main.cpp:13:1: warning: control reaches end of non-void function [-Wreturn-type] } ^