Compilare: user.cpp: In function ‘int solve(int)’: user.cpp:48:74: warning: array subscript has type ‘char’ [-Wchar-subscripts] int startIndex = binarySearchStartIndex(last, i, 0, nextCharIndices[last].size() - 1); ^ user.cpp:51:52: warning: array subscript has type ‘char’ [-Wchar-subscripts] for (int j = startIndex; j < nextCharIndices[last].size(); ++j) { ^ user.cpp:51:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = startIndex; j < nextCharIndices[last].size(); ++j) { ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.cpp:52:46: warning: array subscript has type ‘char’ [-Wchar-subscripts] int candidate = solve(nextCharIndices[last][j]); ^ user.cpp:55:36: warning: array subscript has type ‘char’ [-Wchar-subscripts] child[i] = nextCharIndices[last][j]; ^ user.cpp: In function ‘int main()’: user.cpp:72:31: warning: format ‘%s’ expects argument of type ‘char*’, but argument 2 has type ‘char (*)[20]’ [-Wformat=] code = scanf("%s", &words[n]); ^ user.cpp:66:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("text3.in", "r", stdin); ^ user.cpp:67:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("text3.out", "w", stdout); ^