Compilare: user.cpp: In function ‘int main()’: user.cpp:40:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d %d",&n,&m); ^ user.cpp:44:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&t); ^ user.cpp:125:41: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d %d",&temp,&temp2); ^ cc1plus: warning: iteration 300098u invokes undefined behavior [-Waggressive-loop-optimizations] user.cpp:74:5: note: containing loop for(int i=2;i<=1000000;i++) ^