Compilare: user.cpp: In function ‘void link(const std::vector<int>&, const std::vector<int>&)’: user.cpp:87:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < c0.size(); ++ i) { ^ user.cpp:88:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (j < c1.size() && intervs[c1[j]].y1 <= intervs[c0[i]].y1) { ^ user.cpp:94:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j < c1.size()) ^ user.cpp: In function ‘void test()’: user.cpp:113:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < all_x.size(); ++ i) ^ user.cpp:120:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i <= all_x.size() - 2; ++ i) { ^ user.cpp:127:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j < stones[i].size(); ++ j) ^ user.cpp:142:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 2; i <= all_x.size() - 2; ++ i) ^ user.cpp:150:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < intervs.size(); ++ i) ^