View Compilation Error

0_0_36442744_16584.cpp: In function 'void topo()':
0_0_36442744_16584.cpp:40:24: error: 'x' was not declared in this scope
                 if(val[x]){
                        ^
0_0_36442744_16584.cpp:45:47: error: 'x' was not declared in this scope
                 val[to]=max(0,min(val[to],val[x]-1));
                                               ^
0_0_36442744_16584.cpp:47:35: error: 'x' was not declared in this scope
                 val[to]=max(0,val[x]-1);
                                   ^
0_0_36442744_16584.cpp:49:20: error: 'x' was not declared in this scope
             if(val[x]) vis[to]=1;
                    ^