Compilare: user.cpp: In function ‘int main()’: user.cpp:26:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<len; i++) ^ user.cpp:30:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<len; i++) ^ user.cpp:33:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<len; j++) ^ user.cpp:38:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<strlen(ss); i++) g << ss[i]; ^ user.cpp:56:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int q=0; q<lenj; q++) ^ user.cpp:59:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(pos == leni) break; ^ user.cpp:61:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(pos == leni) ^ user.cpp:78:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<len; j++) g << s[v[i]][j]; ^