View Compilation Error

0_0_7789714_30030.cpp: In function `bool ishw(int)':
0_0_7789714_30030.cpp:20: error: `itoa' undeclared (first use this function)
0_0_7789714_30030.cpp:20: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_7789714_30030.cpp:21: error: `strrev' undeclared (first use this function)