Compilare: user.cpp: In function ‘int main()’: user.cpp:35:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=m;i++) ~^~~ user.cpp:46:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=n;i++) ~^~~ user.cpp:48:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=n;i++) ~^~~ user.cpp: In function ‘unsigned int getint()’: user.cpp:19:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,maxb,1,fin),ptr=0; ^ user.cpp:24:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,maxb,1,fin),ptr=0; ^