Compilare: user.cpp: In function ‘int main()’: user.cpp:20:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secv10.in", "r", stdin); ^ user.cpp:21:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secv10.out", "w", stdout); ^ user.cpp:22:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &T); ^ user.cpp:26:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s + 1); n = strlen(s + 1); ^ user.cpp:27:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a + 1); nn = strlen(a + 1); ^ user.cpp:28:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(b + 1); mm = strlen(b + 1); ^ /tmp/ccxZYJX9.o: In function `main': user.cpp:(.text.startup+0x7f): warning: the `gets' function is dangerous and should not be used.