Compilare: user.cpp: In function ‘int main()’: user.cpp:89:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i < odd.size(); i += 2) { ^ user.cpp:98:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < valid.size(); i++) valid[i] = true; ^ user.cpp:104:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < ord.size(); j++) ^ user.cpp:108:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i <= xx.size(); i++) { ^ user.cpp:113:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i <= yy.size(); i++) { ^ user.cpp:54:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("primar.in","r",stdin); ^ user.cpp:55:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("primar.out","w",stdout); ^ user.cpp:57:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:59:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &P[i].first, &P[i].second); ^