Compilare: user.cpp: In function ‘int main()’: user.cpp:19:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] sol[st[top]] = i; ^ user.cpp:8:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("parantezare.in", "r", stdin); ^ user.cpp:9:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("parantezare.out", "w", stdout); ^ user.cpp:11:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); n = strlen(s); ^ user.cpp:23:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &k); ^ user.cpp:26:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ /tmp/ccVzmLKz.o: In function `main': user.cpp:(.text.startup+0x5a): warning: the `gets' function is dangerous and should not be used.