Compilare: user.cpp: In function ‘int main()’: user.cpp:15:15: warning: unused variable ‘l’ [-Wunused-variable] int i,j,q,l,r,mij,key,sol; ^ user.cpp:15:17: warning: unused variable ‘r’ [-Wunused-variable] int i,j,q,l,r,mij,key,sol; ^ user.cpp:15:19: warning: unused variable ‘mij’ [-Wunused-variable] int i,j,q,l,r,mij,key,sol; ^ user.cpp:15:23: warning: unused variable ‘key’ [-Wunused-variable] int i,j,q,l,r,mij,key,sol; ^ user.cpp:17:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("search.in","r",stdin); ^ user.cpp:18:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("search.out","w",stdout); ^ user.cpp:19:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n",&N,&M); ^ user.cpp:22:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",(a+1)); ^ user.cpp:34:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",&ch); ^