View Compilation Error

0_0_39119336_11060.cpp: In function 'void restart(int)':
0_0_39119336_11060.cpp:9:46: error: 'pre' was not declared in this scope
    9 |         G[i].clear(), val[i] = 0, ww[i] = 0, pre[i] = 0;
      |                                              ^~~