Compilare: user.cpp: In function ‘int main()’: user.cpp:14:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] int initl = v[a].size(); ^ user.cpp:15:24: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (!initl) v[b].push_back({1, i}); ^ user.cpp:16:25: warning: array subscript has type ‘char’ [-Wchar-subscripts] for (int j=idx[a]; j<initl; j++){ ^ user.cpp:17:36: warning: array subscript has type ‘char’ [-Wchar-subscripts] pair <int,int> it = v[a][j]; ^ user.cpp:18:41: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (it.second < i - k) idx[a]++; ^ user.cpp:19:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] else v[b].push_back({it.first + 1, i}), mx = max(mx, it.first + 1); ^