Compilare: user.cpp: In function ‘int main()’: user.cpp:24:35: warning: array subscript has type ‘char’ [-Wchar-subscripts] ans[i-1][i] = cst[str[i-1]][str[i]]; ^ user.cpp:24:43: warning: array subscript has type ‘char’ [-Wchar-subscripts] ans[i-1][i] = cst[str[i-1]][str[i]]; ^ user.cpp:28:33: warning: array subscript has type ‘char’ [-Wchar-subscripts] ans[a][b]=cst[str[a]][str[b]]+ans[a+1][b-1]; ^ user.cpp:28:41: warning: array subscript has type ‘char’ [-Wchar-subscripts] ans[a][b]=cst[str[a]][str[b]]+ans[a+1][b-1]; ^ user.cpp:17:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file_in,"%d ",&n); ^ user.cpp:18:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file_in,"%s ",str); ^ user.cpp:21:44: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file_in,"%d",&cst[i][j]); ^