Compilare: user.cpp: In function ‘int main()’: user.cpp:87:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i <= xx.size(); i++ ) ^ user.cpp:88:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 1; j <= yy.size(); j++) ^ user.cpp:91:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i <= xx.size() + 1; i++) ^ user.cpp:94:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i <= yy.size() + 1; i++) ^ user.cpp:97:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i <= xx.size(); i++ ) ^ user.cpp:98:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 1; j <= yy.size(); j++) ^ user.cpp:42:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colaj.in","r",stdin); ^ user.cpp:43:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colaj.out","w",stdout); ^ user.cpp:45:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &l, &h); ^ user.cpp:48:62: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &xx1[i], &yy1[i], &xx2[i], &yy2[i]); ^