Compilare: main.cpp: In function 'int main()': main.cpp:18:17: warning: unused variable 'r' [-Wunused-variable] int t,n,i,j,r; ^ main.cpp:16:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("doipe.in","r",stdin); ^ main.cpp:17:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("doipe.out","w",stdout); ^ main.cpp:20:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ main.cpp:22:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%c",&n,&ch); ^ main.cpp:23:27: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fgets(s,N+2,stdin); ^