Compilare: main.cpp: In function 'void solve()': main.cpp:48:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:49:52: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for (int i = 0; i < n; ++i) scanf("%d", cost + i); ^ main.cpp:51:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] int u, v; scanf("%d%d", &u, &v); ^ main.cpp: In function 'int main()': main.cpp:66:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("mvc.in", "r", stdin); ^ main.cpp:67:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("mvc.out", "w", stdout); ^