View Compilation Error

0_0_5981150_7239.cpp: In function `int cmp1(const void*, const void*)':
0_0_5981150_7239.cpp:9: error: `strcmp' undeclared (first use this function)
0_0_5981150_7239.cpp:9: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_5981150_7239.cpp: In function `int cmp2(const void*, const void*)':
0_0_5981150_7239.cpp:15: error: `strcmp' undeclared (first use this function)
0_0_5981150_7239.cpp: In function `int cmp3(const void*, const void*)':
0_0_5981150_7239.cpp:27: error: `strcmp' undeclared (first use this function)
0_0_5981150_7239.cpp: In function `int main()':
0_0_5981150_7239.cpp:32: error: `scanf' undeclared (first use this function)
0_0_5981150_7239.cpp:32: error: `EOF' undeclared (first use this function)
0_0_5981150_7239.cpp:36: error: `getchar' undeclared (first use this function)
0_0_5981150_7239.cpp:48: error: `printf' undeclared (first use this function)