Compilare: user.cpp: In function ‘int update(int, int)’: user.cpp:13:12: warning: no return statement in function returning non-void [-Wreturn-type] aib[i]+=nr;} ^ user.cpp: In function ‘int main()’: user.cpp:20:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("swap.in","r",stdin); ^ user.cpp:21:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("swap.out","w",stdout); ^ user.cpp:24:23: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(a+1,50003,stdin); ^ user.cpp:30:52: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c",&ch),f2[ch-96]++,poz[ch-96].push_back(i); ^