Compilare: user.cpp: In function ‘int main()’: user.cpp:10:15: warning: unused variable ‘ans’ [-Wunused-variable] int l, n, ans = 0, t; ^ user.cpp:8:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cifra.in", "r", stdin); ^ user.cpp:9:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cifra.out", "w", stdout); ^ user.cpp:13:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (scanf("%d\n", &t); t > 0; --t) ^ user.cpp:15:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); l = strlen(s); ^ /tmp/ccS7Uncp.o: In function `main': user.cpp:(.text.startup+0x117): warning: the `gets' function is dangerous and should not be used.