Compilare: user.cpp: In function ‘int main()’: user.cpp:39:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("nums.in", "r", stdin); ^ user.cpp:40:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("nums.out", "w", stdout); ^ user.cpp:42:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &M); ^ user.cpp:46:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d ", &tip); ^ user.cpp:51:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &x); ^ user.cpp:55:22: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets (actual + 1); ^ user.cpp:69:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("nums.in", "r", stdin); ^ user.cpp:70:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &M); ^ user.cpp:74:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d ", &tip); ^ user.cpp:78:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d\n", &x); ^ user.cpp:86:22: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets (actual + 1); ^ /tmp/ccU3Bxol.o: In function `main': user.cpp:(.text.startup+0xc7): warning: the `gets' function is dangerous and should not be used.