View Compilation Error

0_0_30379793_26411.cpp: In function 'll solve()':
0_0_30379793_26411.cpp:87:16: error: 'idx' was not declared in this scope
             if(idx == 1)
                ^
0_0_30379793_26411.cpp:90:19: error: 'idx' was not declared in this scope
          index += idx;
                   ^