Compilare: user.cpp: In function ‘int main()’: user.cpp:17:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i1=0,i2=0; i1<str[i-1].size() && i2<str[i].size() && str[i-1][i1]==str[i][i2]; i1++, i2++); ^ user.cpp:17:62: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i1=0,i2=0; i1<str[i-1].size() && i2<str[i].size() && str[i-1][i1]==str[i][i2]; i1++, i2++); ^