View Compilation Error

0_0_18567459_11916.cpp: In function 'int main()':
0_0_18567459_11916.cpp:36:25: error: could not convert 'i' from 'int' to 'node'
       if (isr(i, j, k, l)) {
                         ^
0_0_18567459_11916.cpp:39:33: error: 'check' was not declared in this scope
         if (!check(i, j, k, l, t)) continue;
                                 ^