foo.cc: In function 'void calc(int, int, int, int, int)':
foo.cc:73:48: warning: array subscript has type 'char' [-Wchar-subscripts]
   73 |         q[++tail]=node,sam=S[id].son(sam,a[node]);
      |                                          ~~~~~~^
foo.cc:22:25: note: in definition of macro 'son'
   22 | #define son(x,y) son[x][y]
      |                         ^
foo.cc: In function 'void solve(int)':
foo.cc:97:34: warning: array subscript has type 'char' [-Wchar-subscripts]
   97 |         int sam=S[1].son(1,a[node]),len=(s[1][1]==a[node]),last=1;
      |                            ~~~~~~^
foo.cc:22:25: note: in definition of macro 'son'
   22 | #define son(x,y) son[x][y]
      |                         ^
foo.cc:98:19: warning: unused variable 'rec' [-Wunused-variable]
   98 |         long long rec=ans;
      |                   ^~~
foo.cc:99:14: warning: unused variable 'flag' [-Wunused-variable]
   99 |         bool flag=0;
      |              ^~~~

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