Compilare: main.cpp: In function 'int main()': main.cpp:45:30: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses] sum(fr[nr&1^1][nxt[i+1][cif]][(j * 10 + cif) % k], fr[nr&1][i][j]); ~~^~ main.cpp:17:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("diviz.in","r",stdin); ^ main.cpp:18:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("diviz.out","w",stdout); ^