Main.cc: In function ‘int main()’: Main.cc:60:22: error: request for member ‘push_back’ in ‘aa[i].std::vector::operator[](((std::vector::size_type)j))’, which is of non-class type ‘__gnu_cxx::__alloc_traits >::value_type {aka long long int}’ aa[i][j].push_back(k); ^~~~~~~~~ Main.cc:105:17: error: ‘b’ was not declared in this scope b[i].insert(i); ^ Main.cc:110:26: error: ‘b’ was not declared in this scope for (int y : b[x]) ^ Main.cc:116:32: error: ‘b’ was not declared in this scope for (auto it = b[i].begin(); it != b[i].end();) ^ Main.cc:120:36: error: unable to deduce ‘auto’ from ‘it’ auto it2 = it; ^~ Main.cc:131:13: error: ‘b’ was not declared in this scope b[i].insert(i); ^ Main.cc:144:13: error: ‘ls’ was not declared in this scope ls.clear(); ^~ Main.cc:151:30: error: ‘b’ was not declared in this scope for (int j : b[x]) ^ Main.cc:146:17: warning: unused variable ‘xx’ [-Wunused-variable] int xx; ^~ Main.cc:48:10: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &n); ~~~~~^~~~~~~~~~~~ Main.cc:53:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &sz[i]); ~~~~~^~~~~~~~~~~~~~~~ Main.cc:59:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &k); ~~~~~^~~~~~~~~~~~ Main.cc:76:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &q); ~~~~~^~~~~~~~~~~~ Main.cc:80:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &k); ~~~~~^~~~~~~~~~~~ Main.cc:88:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &x); ~~~~~^~~~~~~~~~~~ Main.cc:102:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int l;scanf("%lld", &l); ~~~~~^~~~~~~~~~~~ Main.cc:109:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &x); ~~~~~^~~~~~~~~~~~ Main.cc:115:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &x); ~~~~~^~~~~~~~~~~~ Main.cc:139:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &q); ~~~~~^~~~~~~~~~~~ Main.cc:143:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &k); ~~~~~^~~~~~~~~~~~ Main.cc:150:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &x); ~~~~~^~~~~~~~~~~~