Compilare: user.cpp: In function ‘int main()’: user.cpp:64:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &T, &N, &M); ^ user.cpp:68:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ", &u, &v); ^ user.cpp:69:19: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(cost); ^ /tmp/ccxteXJ3.o: In function `main': user.cpp:(.text.startup+0x8c): warning: the `gets' function is dangerous and should not be used.