View Compilation Error

0_0_18022770_2827.cpp: In function 'void init()':
0_0_18022770_2827.cpp:56:13: error: 'nex' was not declared in this scope
             nex[th]=ind[j];
             ^
0_0_18022770_2827.cpp:56:21: error: 'ind' was not declared in this scope
             nex[th]=ind[j];
                     ^