Compilare: user.cpp: In function ‘bool ok(int)’: user.cpp:15:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] int poz = v[aux[0]][0], step, j, r = 0; ^ user.cpp:18:38: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (r + grad - 1 < v[aux[i-1]].size()) ^ user.cpp:18:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (r + grad - 1 < v[aux[i-1]].size()) ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~ user.cpp:20:29: warning: array subscript has type ‘char’ [-Wchar-subscripts] poz = v[aux[i-1]][r + grad - 1]; ^ user.cpp:25:31: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (step < v[aux[i]].size() - 1) step <<= 1; ^ user.cpp:25:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (step < v[aux[i]].size() - 1) step <<= 1; ~~~~~^~~~~~~~~~~~~~~~~~~~~~ user.cpp:29:37: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (j + step <= v[aux[i]].size() - 1 && v[aux[i]][j + step] <= poz) ^ user.cpp:29:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j + step <= v[aux[i]].size() - 1 && v[aux[i]][j + step] <= poz) ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~ user.cpp:29:61: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (j + step <= v[aux[i]].size() - 1 && v[aux[i]][j + step] <= poz) ^ user.cpp:35:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (v[aux[i]][j] <= poz) ^ user.cpp:42:35: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (r + grad - 1 >= v[aux[m-1]].size()) ^ user.cpp:42:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (r + grad - 1 >= v[aux[m-1]].size()) ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:75:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] v[s[i]].push_back(i); ^ user.cpp: In function ‘int cb()’: user.cpp:67:12: warning: ‘ind’ may be used uninitialized in this function [-Wmaybe-uninitialized] return ind; ^~~