Compilare: main.cpp: In function 'int main()': main.cpp:41:25: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] curent[k] = NULL; ^~~~ main.cpp:48:29: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] curent[k] = NULL; ^~~~ main.cpp:61:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (it < s[i].size()) ~~~^~~~~~~~~~~~~ main.cpp:77:29: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] curent[k] = NULL; ^~~~ main.cpp:85:25: warning: converting to non-pointer type 'char' from NULL [-Wconversion-null] curent[k] = NULL; ^~~~