View Compilation Error

0_0_6863961_19982.cpp: In function `int main()':
0_0_6863961_19982.cpp:15: error: `sort' undeclared (first use this function)
0_0_6863961_19982.cpp:15: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6863961_19982.cpp:20: error: `abs' undeclared (first use this function)
0_0_6863961_19982.cpp:24: error: `min' undeclared (first use this function)