Compilare: main.cpp: In function 'int main()': main.cpp:22:21: warning: 'last' may be used uninitialized in this function [-Wmaybe-uninitialized] int val, first, last; ^~~~ main.cpp:37:25: warning: 'first' may be used uninitialized in this function [-Wmaybe-uninitialized] for(int i = first - 1; i >= last; i--) { ^