Compilare: user.cpp: In function ‘int main()’: user.cpp:102:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < pts.size() - 1; ++ i) { ^ user.cpp:153:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < angle.size(); ++ i) { ^ user.cpp:89:12: warning: unused variable ‘flag’ [-Wunused-variable] int k, flag, i, j, line, last; ^ user.cpp:89:30: warning: unused variable ‘last’ [-Wunused-variable] int k, flag, i, j, line, last; ^ user.cpp:87:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("laser.in", "r", stdin); ^ user.cpp:88:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("laser.out", "w", stdout); ^ user.cpp:91:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:115:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &coef[i][m + 1]); ^ user.cpp: In member function ‘void SEGMENT::read()’: user.cpp:14:80: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &end1.first, &end1.second, &end2.first, &end2.second); ^