Compilare: main.cpp: In function 'int main()': main.cpp:21:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.in", "r", stdin); ^ main.cpp:22:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dragoni.out", "w", stdout); ^ main.cpp:23:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &p, &N, &M); ^ main.cpp:24:84: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(i=1; i<=N; ++i){Graph[i].push_back(make_pair(0, 0)); scanf("%d", &Power[i]); Ord[i].push_back(make_pair(0, 0));} ^ main.cpp:27:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &z); ^