题目

verify-preorder-serialization-of-a-binary-tree

算法

* 模拟

代码

* 模拟

class Solution {
public:
    bool isValidSerialization(string preorder) {
        if (preorder.empty()) return false;
        istringstream in(preorder);
        vector<string> v;
        string val;
        int d = 0;
        while (getline(in, val, ',')) v.push_back(val);
        for (int i = 0; i < v.size() - 1; ++i) {
            if (v[i] == "#") {
                if (d == 0) return false;
                else --d;
            }
            else ++d;
        }
        return d != 0 ? false : v.back() == "#";
    }
};