View Compilation Error

0_0_6676099_25156.cpp: In function `int main()':
0_0_6676099_25156.cpp:82: error: `scanf' undeclared (first use this function)
0_0_6676099_25156.cpp:82: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6676099_25156.cpp:87: error: `sort' undeclared (first use this function)
0_0_6676099_25156.cpp:92: error: `printf' undeclared (first use this function)