一开始没想到是dp真是罪过

见状态转移想dp

一见到能用dfs做的想dp

int solution(int n, int H, int A, vector<int> h, vector<int> a) {
    int ans=0;
    vector<int>dp(n,0xc0c0c0c0);
    for(int i=0;i<n;i++){
        if(h[i]<H&&a[i]<A)dp[i]=1;
    }
    for (int now = 0; now < n; now++) { 
        for (int pre = 0; pre < n; pre++) {
            if (now == pre) continue;
            if (h[pre] > h[now] && a[pre] > a[now]) {
                dp[now] = max(dp[now], dp[pre] + 1);
            }
        }
        ans = max(ans, dp[now]);
        //cout<<"!"<<ans<<endl;
    }
    return ans;
}