Compilare: main.cpp: In function 'int prim(int, int, int)': main.cpp:21:5: warning: 'cat' may be used uninitialized in this function [-Wmaybe-uninitialized] if(cat==a) niv1--; ^~ main.cpp: In function 'int main()': main.cpp:21:5: warning: 'cat' may be used uninitialized in this function [-Wmaybe-uninitialized] if(cat==a) niv1--; ^~ main.cpp:11:42: note: 'cat' was declared here long long aux=nr*nr, niv1=1, niv2=1, cat; ^~~