Compilare: user.cpp: In function ‘int main()’: user.cpp:40:16: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (a!=0) ^ user.cpp:13:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ec.in","r",stdin); ^ user.cpp:14:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ec.out","w",stdout); ^ user.cpp:15:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld%ld",&n,&k); ^ user.cpp:17:54: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (j=1;j<=n;j++) scanf("%ld",&v[(i-1)*n+j]); ^ user.cpp:22:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",sir); ^