View Compilation Error

0_0_21572506_25032.cpp: In function 'void dfs(int, int)':
0_0_21572506_25032.cpp:27:2: error: 'val' was not declared in this scope
  val[x]=sz[x]*2-1;
  ^
0_0_21572506_25032.cpp: In function 'int main()':
0_0_21572506_25032.cpp:45:4: error: 'A' was not declared in this scope
    A=1.0;
    ^
0_0_21572506_25032.cpp:47:5: error: 'C' was not declared in this scope
     C+=A*(1.0-up[x]);
     ^
0_0_21572506_25032.cpp:48:5: error: 'D' was not declared in this scope
     D+=(B+valg[x])*C;
     ^
0_0_21572506_25032.cpp:48:9: error: 'B' was not declared in this scope
     D+=(B+valg[x])*C;
         ^
0_0_21572506_25032.cpp:50:8: error: 'val' was not declared in this scope
     B+=val[x];
        ^
0_0_21572506_25032.cpp:52:4: error: 'a' was not declared in this scope
    a[i][m+1]+=A;
    ^