Compilare: user.cpp: In function ‘void precalc()’: user.cpp:17:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= s.size(); ++i) { ~~^~~~~~~~~~~ user.cpp: In function ‘int bs(int, int)’: user.cpp:27:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (r + pas <= s.size() && sp[c][r + pas] < val) ~~~~~~~~^~~~~~~~~~~ user.cpp: In function ‘bool ok(int)’: user.cpp:36:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < str.size(); ++i) { ~~^~~~~~~~~~~~