Compilare: user.cpp: In function ‘int query(int, int)’: user.cpp:53:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < fp.v.size(); ++i) { ^ user.cpp:52:7: warning: unused variable ‘a’ [-Wunused-variable] int a = 0, b = fp.v.size() - 1; ^ user.cpp:52:14: warning: unused variable ‘b’ [-Wunused-variable] int a = 0, b = fp.v.size() - 1; ^ user.cpp: In function ‘int main()’: user.cpp:96:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i + 1 < unic_x.size(); ++i) { ^ user.cpp:99:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < s.size(); ++j) if (intersect(fp, s[j])) { ^ user.cpp:69:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("poligon.in", "r", stdin); ^ user.cpp:70:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("poligon.out", "w", stdout); ^ user.cpp:72:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:74:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &px[i], &py[i]); ^ user.cpp:111:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^