Compilare: user.cpp: In function ‘int main()’: user.cpp:123:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k1 = 0; k1 < line[nline].on.size(); k1++) ^ user.cpp:124:58: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k2 = k1 + 1; k2 < line[nline].on.size(); k2++) ^ user.cpp:96:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("geom.in", "r", stdin); ^ user.cpp:97:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("geom.out", "w", stdout); ^ user.cpp:99:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &target); ^ user.cpp:103:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &point[i].x, &point[i].y); ^