Compilare: user.cpp: In function ‘int main()’: user.cpp:19:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<strlen(b)) ^ user.cpp:24:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1;j<strings.size();j+=2) ^ user.cpp:32:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<strings.size();j+=2) ^ user.cpp:35:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1;j<strings.size();j+=2) ^ user.cpp:45:36: warning: operation on ‘i’ may be undefined [-Wsequence-point] c[i-var]=b[i++]; ^ user.cpp:56:40: warning: operation on ‘i’ may be undefined [-Wsequence-point] c[i-var]=b[i++]; ^