foo.cc:85:11: error: redefinition of 'const int MAXN'
   85 | const int MAXN = 100001,MAXM=200001;
      |           ^~~~
foo.cc:14:11: note: 'const int MAXN' previously defined here
   14 | const int MAXN = 100001,MAXM=200001;
      |           ^~~~
foo.cc:85:25: error: redefinition of 'const int MAXM'
   85 | const int MAXN = 100001,MAXM=200001;
      |                         ^~~~
foo.cc:14:25: note: 'const int MAXM' previously defined here
   14 | const int MAXN = 100001,MAXM=200001;
      |                         ^~~~
foo.cc:86:5: error: redefinition of 'int n'
   86 | int n, m, cnt;//n个点，m条边
      |     ^
foo.cc:15:5: note: 'int n' previously declared here
   15 | int n, m, cnt;//n个点，m条边
      |     ^
foo.cc:86:8: error: redefinition of 'int m'
   86 | int n, m, cnt;//n个点，m条边
      |        ^
foo.cc:15:8: note: 'int m' previously declared here
   15 | int n, m, cnt;//n个点，m条边
      |        ^
foo.cc:86:11: error: redefinition of 'int cnt'
   86 | int n, m, cnt;//n个点，m条边
      |           ^~~
foo.cc:15:11: note: 'int cnt' previously declared here
   15 | int n, m, cnt;//n个点，m条边
      |           ^~~
foo.cc:87:5: error: redefinition of 'int head [100001]'
   87 | int head[MAXN];
      |     ^~~~
foo.cc:16:5: note: 'int head [100001]' previously declared here
   16 | int head[MAXN];
      |     ^~~~
foo.cc:88:5: error: redefinition of 'int depth [100001]'
   88 | int depth[MAXN],ind[MAXN];//节点在拓扑序中的深度、节点入度
      |     ^~~~~
foo.cc:17:5: note: 'int depth [100001]' previously declared here
   17 | int depth[MAXN],ind[MAXN];//节点在拓扑序中的深度、节点入度
      |     ^~~~~
foo.cc:88:17: error: redefinition of 'int ind [100001]'
   88 | int depth[MAXN],ind[MAXN];//节点在拓扑序中的深度、节点入度
      |                 ^~~
foo.cc:17:17: note: 'int ind [100001]' previously declared here
   17 | int depth[MAXN],ind[MAXN];//节点在拓扑序中的深度、节点入度
      |                 ^~~
foo.cc:90:8: error: redefinition of 'struct Edge'
   90 | struct Edge
      |        ^~~~
foo.cc:19:8: note: previous definition of 'struct Edge'
   19 | struct Edge
      |        ^~~~
foo.cc:93:2: error: conflicting declaration 'int edge [200001]'
   93 | }edge[MAXM];
      |  ^~~~
foo.cc:22:2: note: previous declaration as 'Edge edge [200001]'
   22 | }edge[MAXM];
      |  ^~~~
foo.cc:95:6: error: redefinition of 'void add_edge(int, int)'
   95 | void add_edge(int u, int v)
      |      ^~~~~~~~
foo.cc:24:6: note: 'void add_edge(int, int)' previously defined here
   24 | void add_edge(int u, int v)
      |      ^~~~~~~~
foo.cc:102:6: error: redefinition of 'void topo()'
  102 | void topo()
      |      ^~~~
foo.cc:31:6: note: 'void topo()' previously defined here
   31 | void topo()
      |      ^~~~
foo.cc:128:5: error: redefinition of 'int main()'
  128 | int main()
      |     ^~~~
foo.cc:57:5: note: 'int main()' previously defined here
   57 | int main()
      |     ^~~~
foo.cc: In function 'int main()':
foo.cc:60:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   60 |     scanf("%d%d",&n,&m);
      |     ~~~~~^~~~~~~~~~~~~~
foo.cc:63:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   63 |         scanf("%d%d",&u,&v);
      |         ~~~~~^~~~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:131:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  131 |     scanf("%d%d",&n,&m);
      |     ~~~~~^~~~~~~~~~~~~~
foo.cc:134:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  134 |         scanf("%d%d",&u,&v);
      |         ~~~~~^~~~~~~~~~~~~~

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