View Compilation Error

0_0_24360810_18663.cpp:10:1: error: 'Node' does not name a type
 Node nodes[N];
 ^
0_0_24360810_18663.cpp: In function 'void build(int, int, int)':
0_0_24360810_18663.cpp:13:5: error: 'nodes' was not declared in this scope
     nodes[i].lef_val = lef_val;
     ^
0_0_24360810_18663.cpp: In function 'void add_val(int)':
0_0_24360810_18663.cpp:22:9: error: 'nodes' was not declared in this scope
     if (nodes[i].lef_val >= lef && nodes[i].rig_val <= rig) {
         ^
0_0_24360810_18663.cpp: In function 'void dfs(int, int)':
0_0_24360810_18663.cpp:31:12: error: 'nodes' was not declared in this scope
     cum += nodes[i].count;
            ^
0_0_24360810_18663.cpp: In function 'int main()':
0_0_24360810_18663.cpp:44:16: error: 'nodes' was not declared in this scope
         memset(nodes, 0, sizeof(Node) * N);
                ^