Compilare: user.cpp: In function ‘int main()’: user.cpp:64:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("suma5.in","r",stdin); ^ user.cpp:65:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("suma5.out","w",stdout); ^ user.cpp:66:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N,&M); ^ user.cpp:72:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] { scanf("%d", &x); ^ user.cpp:78:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] { scanf("%d", &op); ^ user.cpp:79:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] if(op==0) { scanf("%d%d%d", &x,&y,&vl); update(1,1,N,x,y,vl); } ^ user.cpp:80:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] else if(op==1) { scanf("%d%d", &x,&y); afis=query(1,1,N,x,y); printf("%lld\n", afis.sg); } ^