View Compilation Error

0_0_21930192_31864.cpp: In function 'int main()':
0_0_21930192_31864.cpp:29:6: error: 'i' was not declared in this scope
  for(i=0;i<n-1;i++)
      ^
0_0_21930192_31864.cpp:31:20: error: 'i' was not declared in this scope
  printf("%d\n",str[i].x);
                    ^