Compilare: main.cpp: In function 'int main()': main.cpp:107:48: warning: unused variable 'ans' [-Wunused-variable] for (int X1, Y1, X2, Y2, node, n1, n2, d = 0, ans; Q; --Q, d = 0){ ^~~ main.cpp:84:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.in", "r", stdin); ^ main.cpp:85:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("pirati.out", "w", stdout); ^ main.cpp:87:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &N, &M, &Q); ^ main.cpp:108:44: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf(" %d %d %d %d", &X1, &Y1, &X2, &Y2); ^ main.cpp: In function 'int read_val()': main.cpp:21:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf(" %c", &v); ^