Compilare: user.cpp: In function ‘pr cauta(std::vector<std::pair<int, int> >&, int)’: user.cpp:44:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (step=1;step<a.size();step<<=1); ^ user.cpp:46:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i+step<a.size() && a[i+step].first<=x) { ^ user.cpp: In function ‘int main()’: user.cpp:71:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rest.in","r",stdin); ^ user.cpp:72:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rest.out","w",stdout); ^ user.cpp:73:33: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,buffersize,stdin); l=0; ^ user.cpp:83:33: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,1,buffersize,stdin); l=0; ^ user.cpp: In function ‘void read(T&) [with T = short unsigned int]’: user.cpp:21:18: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] l=0; fread(buffer,1,buffersize,stdin); ^ user.cpp:28:18: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] l=0; fread(buffer,1,buffersize,stdin); ^ user.cpp: In function ‘void read(T&) [with T = int]’: user.cpp:21:18: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] l=0; fread(buffer,1,buffersize,stdin); ^ user.cpp:28:18: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] l=0; fread(buffer,1,buffersize,stdin); ^