Compilare: main.cpp: In function 'void ins(std::__cxx11::string, int)': main.cpp:60:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp: In function 'void get_sum()': main.cpp:74:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp: In function 'void update(int)': main.cpp:113:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(a[i].x.size()!=len) ~~~~~~~~~~~~~^~~~~ main.cpp:121:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp:123:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i+len-1>=s.size()) ~~~~~~~^~~~~~~~~~