Compilare: main.cpp: In function 'std::vector<std::pair<int, int> > dpmerge(std::vector<std::pair<int, int> >, std::vector<std::pair<int, int> >)': main.cpp:39:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v2.size();i++) v2[i].first++; ~^~~~~~~~~~ main.cpp:43:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<v1.size() or j<v2.size()) ~^~~~~~~~~~ main.cpp:43:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<v1.size() or j<v2.size()) ~^~~~~~~~~~ main.cpp:45:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j>=v2.size()) {aux.push_back(v1[i]);i++;} ~^~~~~~~~~~~ main.cpp:46:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(i>=v1.size()) {aux.push_back(v2[j]);j++;} ~^~~~~~~~~~~ main.cpp:52:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<aux.size();i++) ~^~~~~~~~~~~ main.cpp: In function 'std::vector<std::pair<int, int> > dpmerge1(std::vector<std::pair<int, int> >, std::vector<std::pair<int, int> >)': main.cpp:71:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<v1.size() or j<v2.size()) ~^~~~~~~~~~ main.cpp:71:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<v1.size() or j<v2.size()) ~^~~~~~~~~~ main.cpp:73:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j>=v2.size()) {aux.push_back(v1[i]);i++;} ~^~~~~~~~~~~ main.cpp:74:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(i>=v1.size()) {aux.push_back(v2[j]);j++;} ~^~~~~~~~~~~ main.cpp:80:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<aux.size();i++) ~^~~~~~~~~~~ main.cpp: In function 'void dfsdown(int, int)': main.cpp:97:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ~^~~~~~~~~~~~~~ main.cpp: In function 'void dfsup(int, int)': main.cpp:138:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<ans.size()-1;i++) ~^~~~~~~~~~~~~ main.cpp:140:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ~^~~~~~~~~~~~~~ main.cpp: In member function 'char InParser::read_ch()': main.cpp:155:29: 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, 4096, fin); ^