View Compilation Error

934771_0_0_26018.cpp: In function `int cmp(const void*, const void*)':
934771_0_0_26018.cpp:14: error: invalid use of undefined type `struct m'
934771_0_0_26018.cpp:12: error: forward declaration of `struct m'
934771_0_0_26018.cpp:14: error: invalid use of undefined type `struct m'
934771_0_0_26018.cpp:12: error: forward declaration of `struct m'
934771_0_0_26018.cpp: In function `int main()':
934771_0_0_26018.cpp:56: error: `qsort' undeclared (first use this function)
934771_0_0_26018.cpp:56: error: (Each undeclared identifier is reported only once for each function it appears in.)
934771_0_0_26018.cpp:60: error: `max' undeclared (first use this function)