Compilare: main.cpp: In function 'int main()': main.cpp:31:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("euclid.in","r",stdin); ^ main.cpp:32:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("euclid.out","w",stdout); ^ main.cpp:33:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ main.cpp:37:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &h, &w); ^ main.cpp:40:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^ main.cpp:35:8: warning: iteration 403 invokes undefined behavior [-Waggressive-loop-optimizations] lg[i]=lg[(i>>1)]+1; ~~~~~^~~~~~~~~~~~~ main.cpp:34:15: note: within this loop for(int i=2;i<=405;++i) ~^~~~~