Compilare: main.cpp: In function 'int main()': main.cpp:73:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(l=0; l<vec[j].size(); l++) ~^~~~~~~~~~~~~~ main.cpp:45:46: warning: unused variable 'dr' [-Wunused-variable] int n,q,i,l,r,cnt=0,j,valmax=0,cnt1=0,st,dr; ^~ main.cpp: In function 'char next_char()': main.cpp:17:32: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,val,stdin); ^ main.cpp: In function 'int main()': main.cpp:43:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("deletegcd.in","r",stdin); ^ main.cpp:44:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("deletegcd.out","w",stdout); ^