View Compilation Error

0_0_1184083_18255.cpp: In function `void quick_sort(node*, int, int)':
0_0_1184083_18255.cpp:21: error: `strcmpi' undeclared (first use this function)
0_0_1184083_18255.cpp:21: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_1184083_18255.cpp: In function `int main()':
0_0_1184083_18255.cpp:49: error: `abs' undeclared (first use this function)