View Compilation Error

0_0_26492097_17334.cpp: In function 'int main()':
0_0_26492097_17334.cpp:39:28: error: 'nodes' was not declared in this scope
             for (auto it = nodes.begin(); it != nodes.end(); it++) {
                            ^
0_0_26492097_17334.cpp:48:13: error: 'in' was not declared in this scope
             in[y]++;
             ^
0_0_26492097_17334.cpp:49:17: error: 'graph' was not declared in this scope
             if (graph.find(x) == graph.end()) {
                 ^
0_0_26492097_17334.cpp:52:17: error: 'graph' was not declared in this scope
             if (graph.find(y) == graph.end()) {
                 ^
0_0_26492097_17334.cpp:55:13: error: 'graph' was not declared in this scope
             graph[x].push_back(y);
             ^
0_0_26492097_17334.cpp:57:13: error: 'nodes' was not declared in this scope
             nodes.insert(x);
             ^