Compilare: main.cpp: In function 'int main()': main.cpp:10:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sumdiv2.in","r", stdin); ^ main.cpp:11:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sumdiv2.out","w", stdout); ^ main.cpp:27:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n); ^ main.cpp:31:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n",&a,&b); ^ main.cpp:24:50: warning: iteration 1000004 invokes undefined behavior [-Waggressive-loop-optimizations] for(int i=1;i<=1000005;i++) sp[i]=sp[i-1]+sume[i]; ~~~~~~^ main.cpp:24:15: note: within this loop for(int i=1;i<=1000005;i++) sp[i]=sp[i-1]+sume[i]; ~^~~~~~~~~