Compilare: user.cpp: In function ‘bool solve()’: user.cpp:12:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (s[p] == ' ' && p < s.size()) ^ user.cpp:15:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (p < s.size() && s[p] == ' ' ) ^ user.cpp:17:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (p + 1 < s.size() && s[p] == 'O' && s[p + 1] == 'R') ^ user.cpp:23:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (p < s.size() && s[p] == ' ') ^ user.cpp: In function ‘bool fact()’: user.cpp:30:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (s[p] == ' ' && p < s.size()) ^ user.cpp:33:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (p + 2 < s.size() && s[p] == 'A' && s[p + 1] == 'N' && s[p + 2] == 'D') ^ user.cpp:39:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (p < s.size() && (s[p] == ' ')) ^ user.cpp: In function ‘bool term()’: user.cpp:46:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (s[p] == ' ' && p < s.size()) ^ user.cpp:54:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if (p + 2 < s.size() && s[p] == 'N' && s[p + 1] == 'O' && s[p + 2] == 'T') ^ user.cpp:59:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if (p + 3 < s.size() && s[p] == 'T' && s[p + 1] == 'R' && s[p + 2] == 'U' && s[p + 3] == 'E') ^ user.cpp:64:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if (p + 4 < s.size() && s[p] == 'F' && s[p + 1] == 'A' && s[p + 2] == 'L' && s[p + 3] == 'S' && s[p + 4] == 'E') ^ user.cpp:74:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (p < s.size() && (s[p] == ' ')) ^