Compilare: main.cpp: In function 'int main()': main.cpp:80:24: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations] T.a[i][i+1]=1; ~~~~~~~~~~~^~ main.cpp:79:23: note: within this loop for(int i=1; i<=3; i++) ~^~~ main.cpp:80:23: warning: array subscript is above array bounds [-Warray-bounds] T.a[i][i+1]=1; ~~~~~~~~~~^