View Compilation Error

0_0_13372474_16028.cpp: In function 'void PreOrder(int, int, int)':
0_0_13372474_16028.cpp:77:20: error: 'printf' was not declared in this scope
0_0_13372474_16028.cpp:79:21: error: 'printf' was not declared in this scope
0_0_13372474_16028.cpp: In function 'bool run()':
0_0_13372474_16028.cpp:91:16: error: 'scanf' was not declared in this scope