Compilare: user.cpp: In function ‘void read()’: user.cpp:18:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i < (s2.size() / 2); i++){ ^ user.cpp:26:68: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=s2.size() - 1; i >= (s2.size() / 2) + (s2.size() % 2); i--){ ^ user.cpp: In function ‘void Z1()’: user.cpp:41:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1; i<g1.size(); i++){ ^ user.cpp: In function ‘void Z2()’: user.cpp:59:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1; i<g2.size(); i++){ ^ user.cpp: In function ‘int solve()’: user.cpp:74:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i= (s2.size() / 2); i<g1.size(); i++){ ^ user.cpp:80:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=1; i<=(s2.size() / 2); i++){ ^ user.cpp:83:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^