Compilare: main.cpp: In function 'void ins(std::__cxx11::string, int)': main.cpp:64:18: 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:76:18: 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:134:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp:136:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i+len-1>=s.size()) ~~~~~~~^~~~~~~~~~