/in/foo.cc: In function 'void add(char*)':
/in/foo.cc:14:26: warning: array subscript has type 'char' [-Wchar-subscripts]
   if(!a[cur].son[num[s[i]]]) a[cur].son[num[s[i]]]=++cnt,a[cnt].vis=0;
                          ^
/in/foo.cc:14:49: warning: array subscript has type 'char' [-Wchar-subscripts]
   if(!a[cur].son[num[s[i]]]) a[cur].son[num[s[i]]]=++cnt,a[cnt].vis=0;
                                                 ^
/in/foo.cc:15:26: warning: array subscript has type 'char' [-Wchar-subscripts]
   cur=a[cur].son[num[s[i]]];
                          ^
/in/foo.cc: In function 'void match()':
/in/foo.cc:38:26: warning: array subscript has type 'char' [-Wchar-subscripts]
   cur=a[cur].son[num[x[i]]];t=cur;
                          ^
/in/foo.cc: In function 'int find(int)':
/in/foo.cc:46:29: warning: array subscript has type 'char' [-Wchar-subscripts]
   cur=a[cur].son[num[s[i][j]]];
                             ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:53:28: warning: unused variable 'j' [-Wunused-variable]
  scanf("%d%d",&n,&m);int i,j;
                            ^