Compilare: user.cpp: In function ‘bool sc(std::string, std::string)’: user.cpp:38:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0,j=-1; i<s.size(); i++) ^ user.cpp:41:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=1; j<x.size(); j++) ^ user.cpp:43:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j==x.size()) return true; ^ user.cpp: In function ‘void adauga(std::string&, std::string)’: user.cpp:51:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=-1,i=s.size()-x.size(); i<s.size(); i++,j=-1) ^ user.cpp:55:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<x.size(); j++) ^ user.cpp:56:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i+j>=s.size()) s=s+x[j]; else ^ user.cpp:58:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j==x.size()) return; ^ user.cpp: At global scope: user.cpp:63:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main() ^ user.cpp: In function ‘int main()’: user.cpp:67:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<a.size(); i++) ^ user.cpp:73:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<a.size(); i++) ^ user.cpp:77:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1; i<unu.size(); i++) ^