Compilare: user.cpp: In function ‘int main()’: user.cpp:18:15: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(!c[k]) ^ user.cpp:6:79: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sume.in","r",stdin),freopen("sume.out","w",stdout),scanf("%d",&n); ^ user.cpp:6:79: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] user.cpp:6:79: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] user.cpp:8:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",a+i); ^