Compilare: main.cpp: In function 'int main()': main.cpp:27:28: warning: use of 'll' length modifier with 'f' type character has either no effect or undefined behavior [-Wformat=] scanf("%llf",&v[i][j]); ^ main.cpp:22:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("gauss.in","r",stdin); ^ main.cpp:23:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("gauss.out","w",stdout); ^ main.cpp:24:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&m,&n); ^ main.cpp:27:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%llf",&v[i][j]); ^