Compilare: main.cpp: In function 'int main()': main.cpp:24:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sum2.in","r",stdin); ^ main.cpp:25:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sum2.out","w",stdout); ^ main.cpp:27:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n,&st,&dr); ^ main.cpp:29:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &s[i]), s[i]+=s[i-1]; ^