Compilare: user.cpp: In function ‘int calc(int, int, int, int)’: user.cpp:27:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i >= s[id1].size() && j >= s[id2].size()) return 0; ^ user.cpp:27:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i >= s[id1].size() && j >= s[id2].size()) return 0; ^ user.cpp:28:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j >= s[id2].size() && i < s[id1].size()) return inf; ^ user.cpp:28:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j >= s[id2].size() && i < s[id1].size()) return inf; ^ user.cpp:34:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i < s[id1].size()) { ^ user.cpp: In function ‘void backk(int)’: user.cpp:52:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = i + 1; j < s.size(); j++) { ^ user.cpp: In function ‘void solve()’: user.cpp:74:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i < s.size(); ++i) { ^ user.cpp:84:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); ++i) ^ user.cpp:87:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = i + 1; j < s.size() && ok; ++j) { ^