问回溯算法总是使用递归吗？

EN

boolean solve(Node n) {
    put node n on the stack;
    while the stack is not empty {
        if the node at the top of the stack is a leaf {
            if it is a goal node, return true
            else pop it off the stack
        }
        else {
            if the node at the top of the stack has untried children
                push the next untried child onto the stack
            else pop the node off the stack

    }
    return false
}