Compilare: user.cpp: In function ‘void refresh_dfs(nod*&, int)’: user.cpp:39:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (q->urm[sir[i][j]]) ^ user.cpp:40:37: warning: array subscript has type ‘char’ [-Wchar-subscripts] q = q->urm[sir[i][j]]; ^ user.cpp: In function ‘int main()’: user.cpp:81:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (q->urm[sir[i][j]] == 0) q->urm[sir[i][j]] = new nod; ^ user.cpp:81:57: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (q->urm[sir[i][j]] == 0) q->urm[sir[i][j]] = new nod; ^ user.cpp:82:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] q = q->urm[sir[i][j]]; ^ user.cpp:63:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("adn2.in", "r", stdin); ^ user.cpp:64:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("adn2.out", "w", stdout); ^ user.cpp:67:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &T); ^ user.cpp:71:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d\n", &N, &M); ^ user.cpp:75:26: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets (sir[i] + 1); ^ In file included from /usr/include/stdio.h:934:0, from /usr/include/c++/4.8/cstdio:42, from user.cpp:1: In function ‘char* gets(char*)’, inlined from ‘int main()’ at user.cpp:75:26: /usr/include/i386-linux-gnu/bits/stdio2.h:230:28: warning: call to ‘__gets_warn’ declared with attribute warning: please use fgets or getline instead, gets can't specify buffer size [enabled by default] return __gets_warn (__str); ^ /tmp/ccpw8nNW.o: In function `main': user.cpp:(.text.startup+0xee): warning: the `gets' function is dangerous and should not be used.