Compilare: user.cpp: In function ‘void Intersect(int, int)’: user.cpp:98:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < VertexCircle.size() && OK; ++ k) ^ user.cpp:107:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < VertexCircle.size() && OK; ++ k) ^ user.cpp: In function ‘int main()’: user.cpp:148:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < VertexCircle.size(); ++ j) ^ user.cpp:151:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < Vertex.size() && OK; ++ k) ^ user.cpp:115:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerc.in", "r", stdin); ^ user.cpp:116:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cerc.out", "w", stdout); ^ user.cpp:118:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i", &N); ^ user.cpp:121:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i %i %i", &X[i], &Y[i], &R[i]); ^