LeetCode *354. 俄罗斯套娃信封问题（动态规划）

class Solution {
public:
    static bool cmp(vector<int> arr, vector<int> brr) {
        return arr[0] == brr[0] ? brr[1] < arr[1] : arr[0] < brr[0];
    }

    int maxEnvelopes(vector<vector<int>>& envelopes) {
        int res = 1;
        sort(envelopes.begin(), envelopes.end(), cmp);
        vector<int> dp(envelopes.size(), 1);
        for (int i = 0; i < envelopes.size(); i++) {
            for (int j = 0; j < i; j++) {
                if (envelopes[i][3] > envelopes[j][4]) {
                    dp[i] = max(dp[i], dp[j] + 1);
                    res = max(res, dp[i]);
                }
            }
        }
        return res;
    }
};