Compilare: user.cpp: In function ‘void rm_edge(int, int)’: user.cpp:67:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < list[s].size(); i++) { ^ user.cpp: In function ‘void solve(const std::vector<int>&)’: user.cpp:91:9: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ user.cpp: In function ‘int main()’: user.cpp:122:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kdist.in","r",stdin); ^ user.cpp:123:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kdist.out","w",stdout); ^ user.cpp:125:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:127:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp:133:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &col[i]); ^