Compilare: user.cpp: In function ‘int main()’: user.cpp:41:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] L[x[i]] = i; ^ user.cpp:45:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (L[x[i]] == i && !killed[x[i]]) { ^ user.cpp:45:41: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (L[x[i]] == i && !killed[x[i]]) { ^ user.cpp:47:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (!killed[x[j]]) ^ user.cpp:49:36: warning: array subscript has type ‘char’ [-Wchar-subscripts] killed[x[j]] = 1; ^ user.cpp:57:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (!killed[x[i]]) ^ user.cpp:34:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("calandrinon.in", "r", stdin); ^ user.cpp:35:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("calandrinon.out", "w", stdout); ^ user.cpp:38:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &n); ^ user.cpp:39:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(x + 1); ^ /tmp/ccR50p0z.o: In function `main': user.cpp:(.text.startup+0x6a): warning: the `gets' function is dangerous and should not be used.