View Compilation Error

0_0_2600833_669.cpp: In function `int hefa(int, int, int, int, int)':
0_0_2600833_669.cpp:19: error: `abs' undeclared (first use this function)
0_0_2600833_669.cpp:19: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2600833_669.cpp: In function `int zhao(int, int, int, int, int)':
0_0_2600833_669.cpp:56: error: `memset' undeclared (first use this function)
0_0_2600833_669.cpp: In function `int main()':
0_0_2600833_669.cpp:102: error: `memset' undeclared (first use this function)