Compilare: user.cpp: In function ‘int main()’: user.cpp:36:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sobo.in", "r", stdin); ^ user.cpp:37:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sobo.out", "w", stdout); ^ user.cpp:41:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n", &n, &l); ^ user.cpp:44:21: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(v[i].s); ^ user.cpp:47:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &cost[i]); ^ /tmp/ccFrjrqG.o: In function `main': user.cpp:(.text.startup+0x8d): warning: the `gets' function is dangerous and should not be used.