Compilare: user.cpp: In function ‘int main()’: user.cpp:59:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cameleoni.in", "r", stdin); ^ user.cpp:60:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cameleoni.out", "w", stdout); ^ user.cpp:61:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n%c %c %c %c", &n, &ca, &cb, &cc, &cd); ^ user.cpp:74:54: warning: iteration 2u invokes undefined behavior [-Waggressive-loop-optimizations] a.matr[i][j] = (i != j) && ((i ^ j) & -(i ^ j)); ^ user.cpp:72:3: note: containing loop for(i = 0; i < 16; i++) ^ user.cpp:74:54: warning: iteration 2u invokes undefined behavior [-Waggressive-loop-optimizations] a.matr[i][j] = (i != j) && ((i ^ j) & -(i ^ j)); ^ user.cpp:73:5: note: containing loop for(j = 0; j < 16; j++) ^