View Compilation Error

0_0_8903931_7171.cpp: In function `int main()':
0_0_8903931_7171.cpp:4: error: `scanf' undeclared (first use this function)
0_0_8903931_7171.cpp:4: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_8903931_7171.cpp:18: error: `strcmp' undeclared (first use this function)
0_0_8903931_7171.cpp:20: error: `strcpy' undeclared (first use this function)
0_0_8903931_7171.cpp:32: error: `printf' undeclared (first use this function)