Compilare: main.cpp: In function 'void read()': main.cpp:21:48: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations] for(j = 1; j <=3; j++) B[i][j] = A[i][j]; ~~~~~~^ main.cpp:21:22: note: within this loop for(j = 1; j <=3; j++) B[i][j] = A[i][j]; ~~^~~ main.cpp:15:41: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations] for(j = 1; j <= 3; j++) A[i][j] = 0 ; ~~~~~~~~^~~ main.cpp:15:22: note: within this loop for(j = 1; j <= 3; j++) A[i][j] = 0 ; ~~^~~~ main.cpp: In function 'void multiply_m(int (*)[3], int (*)[3])': main.cpp:43:29: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations] A[i][j] = C[i][j]; ~~~~~~^ main.cpp:42:22: note: within this loop for(j = 1; j <= 3; j++) ~~^~~~ main.cpp:37:21: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations] C[i][j] = s; ~~~~~~~~^~~ main.cpp:30:22: note: within this loop for(j = 1; j <= 3; j++) ~~^~~~ main.cpp: In function 'void read()': main.cpp:21:48: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations] for(j = 1; j <=3; j++) B[i][j] = A[i][j]; ~~~~~~^ main.cpp:20:18: note: within this loop for(i = 1; i <= 3; i++) ~~^~~~ main.cpp:15:41: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations] for(j = 1; j <= 3; j++) A[i][j] = 0 ; ~~~~~~~~^~~ main.cpp:14:18: note: within this loop for(i = 1; i <= 3; i++) ~~^~~~ main.cpp:15:39: warning: array subscript is above array bounds [-Warray-bounds] for(j = 1; j <= 3; j++) A[i][j] = 0 ; ~~~~~~^ main.cpp:18:8: warning: array subscript is above array bounds [-Warray-bounds] A[3][2] = 1; ~~~^ main.cpp:21:48: warning: array subscript is above array bounds [-Warray-bounds] for(j = 1; j <=3; j++) B[i][j] = A[i][j]; ~~~~~~^ main.cpp:21:38: warning: array subscript is above array bounds [-Warray-bounds] for(j = 1; j <=3; j++) B[i][j] = A[i][j];