View Compilation Error

0_0_12819934_4679.cpp: In function `int main()':
0_0_12819934_4679.cpp:11: error: `scanf' undeclared (first use this function)
0_0_12819934_4679.cpp:11: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_12819934_4679.cpp:13: error: `memset' undeclared (first use this function)
0_0_12819934_4679.cpp:28: error: `printf' undeclared (first use this function)