Compilare: user.cpp: In function ‘void Solve(int)’: user.cpp:73:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i + 1 < reach.size(); i += 2) ^ user.cpp: In function ‘int main()’: 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("overlap.in", "r", stdin); ^ user.cpp:89:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("overlap.out", "w", stdout); ^ user.cpp:90:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:94:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &init[i].x, &init[i].y); ^