View Compilation Error

0_0_33894810_23117.cpp: In function 'int main()':
0_0_33894810_23117.cpp:188:12: error: no match for 'operator=' (operand types are 'node' and 'int')
    tree[i] = 0;
            ^
0_0_33894810_23117.cpp:188:12: note: candidates are:
0_0_33894810_23117.cpp:20:9: note: node& node::operator=(const node&)
 struct  node
         ^
0_0_33894810_23117.cpp:20:9: note:   no known conversion for argument 1 from 'int' to 'const node&'
0_0_33894810_23117.cpp:20:9: note: node& node::operator=(node&&)
0_0_33894810_23117.cpp:20:9: note:   no known conversion for argument 1 from 'int' to 'node&&'