Compilare: user.cpp: In function ‘int main()’: user.cpp:137:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("patrate.in", "r", stdin); ^ user.cpp:138:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("patrate.out", "w", stdout); ^ user.cpp:140:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:142:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp: In function ‘bool inside(int, int, int, int, int, int, const std::pair<int, int>&)’: user.cpp:15:5: warning: ‘y1’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (l > r) { ^ user.cpp:23:19: note: ‘y1’ was declared here int x, y, x1, y1; ^ user.cpp:15:5: warning: ‘x1’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (l > r) { ^ user.cpp:23:15: note: ‘x1’ was declared here int x, y, x1, y1; ^ user.cpp:15:5: warning: ‘y’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (l > r) { ^ user.cpp:23:12: note: ‘y’ was declared here int x, y, x1, y1; ^ user.cpp:15:5: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (l > r) { ^ user.cpp:23:9: note: ‘x’ was declared here int x, y, x1, y1; ^