Compilare: main.cpp: In function 'int main()': main.cpp:37:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<change[c-'a'].size();j++){ ~^~~~~~~~~~~~~~~~~~~~~ main.cpp:51:77: warning: array subscript has type 'char' [-Wchar-subscripts] d[i][j][lit] |= (d[i][k][split[lit][p].first] & d[k+1][j][split[lit][p].second]); ^ main.cpp:51:111: warning: array subscript has type 'char' [-Wchar-subscripts] d[i][j][lit] |= (d[i][k][split[lit][p].first] & d[k+1][j][split[lit][p].second]); ^ main.cpp:14:27: warning: unused variable 'l1' [-Wunused-variable] int r,m,i,j,k,p,lit,n,l1,l2; ^~ main.cpp:14:30: warning: unused variable 'l2' [-Wunused-variable] int r,m,i,j,k,p,lit,n,l1,l2; ^~ main.cpp:16:32: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%d%d\n",&r,&m); ^