Compilare: user.cpp: In function ‘int main()’: user.cpp:49:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("permutare2.in","r",stdin); ^ user.cpp:50:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("permutare2.out","w",stdout); ^ user.cpp:51:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &M,&N); ^ user.cpp:53:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:55:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^ user.cpp:65:42: warning: ‘sol’ may be used uninitialized in this function [-Wmaybe-uninitialized] val=val+1LL*(P-L)*a[P]-S[P-1]+S[L-1]; ^ user.cpp:64:16: warning: ‘sol’ may be used uninitialized in this function [-Wmaybe-uninitialized] val=S[R]-S[P]-1LL*(R-P)*a[P]; ^