Compilare: main.cpp: In function 'int main()': main.cpp:85:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arb.in", "r", stdin); ^ main.cpp:86:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arb.out", "w", stdout); ^ main.cpp:88:53: 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",&a[i]) ; ^ main.cpp:91:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&b) , b -- ; ^ main.cpp:99:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&node,&x) ; ^