Compilare: user.cpp: In function ‘int main()’: user.cpp:14:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<strlen(s); i++) ^ user.cpp:19:28: warning: deleting array ‘st[(++ d)]’ [enabled by default] delete[] st[++d]; ^ user.cpp:28:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int b=0; b<strlen(st[j]); b++) ^ user.cpp:48:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int b=0; b<strlen(file[k]); b++) ^