View Compilation Error

0_0_13637682_13102.cpp:86:6: error: expected constructor, destructor, or type conversion before '(' token
 qsort(b,c,sizeof(Point),cmp_y);
      ^
0_0_13637682_13102.cpp:87:6: error: expected constructor, destructor, or type conversion before '(' token
 qsort(a,n,sizeof(Point),cmp_x);
      ^
0_0_13637682_13102.cpp: In function 'int cmp_x(const void*, const void*)':
0_0_13637682_13102.cpp:88:5: error: redefinition of 'int cmp_x(const void*, const void*)'
 int cmp_x(const void *p1,const void *p2) {
     ^
0_0_13637682_13102.cpp:73:5: note: 'int cmp_x(const void*, const void*)' previously defined here
 int cmp_x(const void *p1,const void *p2) {
     ^