Compilare: user.cpp: In function ‘int sum(int)’: user.cpp:7:9: warning: unused variable ‘k’ [-Wunused-variable] int k,i,j; ^ user.cpp:7:11: warning: unused variable ‘i’ [-Wunused-variable] int k,i,j; ^ user.cpp: In function ‘int main()’: user.cpp:14:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("piata.in","r",stdin); ^ user.cpp:15:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("piata.out","w",stdout); ^ user.cpp:16:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d",&x,&k1,&i1,&k2,&i2); ^