Compilare: main.cpp: In function 'int main()': main.cpp:32:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int p = 0; p < split[lit].size(); ++p) { ~~^~~~~~~~~~~~~~~~~~~ main.cpp:33:39: warning: array subscript has type 'char' [-Wchar-subscripts] f[lit][split[lit][p].first].push_back(split[lit][p].second); ^ main.cpp:43:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<change[c-'a'].size();j++){ ~^~~~~~~~~~~~~~~~~~~~~ main.cpp:64:81: warning: array subscript has type 'char' [-Wchar-subscripts] if ( d[i][j][lit] |= (d[i][k][l1] & d[k+1][j][l2])) ^ main.cpp:15:19: warning: unused variable 'p' [-Wunused-variable] int r,m,i,j,k,p,lit,n,l1,l2; ^ main.cpp:15:30: warning: unused variable 'l2' [-Wunused-variable] int r,m,i,j,k,p,lit,n,l1,l2; ^~ main.cpp:17:32: 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); ^