View Compilation Error

0_0_37711655_1594.cpp: In function 'void add(int)':
0_0_37711655_1594.cpp:59:13: error: 'i' was not declared in this scope
  int l0=pos[i].x0;
             ^
0_0_37711655_1594.cpp: In function 'void del(int)':
0_0_37711655_1594.cpp:77:13: error: 'i' was not declared in this scope
  int l0=pos[i].x0;
             ^