C++ 解法, 执行用时: 2ms, 内存消耗: 504KB, 提交时间: 2020-10-31

class Cards {
public:
    int cardGame(vector<int> A, int n) {
        vector<vector<int>> a(n, vector<int>(n, 0)), b=a;
        for(int j=0; j<n; j++){
            a[j][j] = A[j];
            b[j][j] = 0;
            for(int i=j-1; i>=0; i--){
                a[i][j] = max(A[i]+b[i+1][j], A[j]+b[i][j-1]);
                b[i][j] = min(a[i+1][j], a[i][j-1]);
            }
        }
        return max(a[0][n-1], b[0][n-1]);
    }
};

C++ 解法, 执行用时: 2ms, 内存消耗: 504KB, 提交时间: 2020-09-15

class Cards {
public:
    int cardGame(vector<int> A, int n) {
        int i,j,res;
        vector<vector<int>> first(n,vector<int>(n,0)),second(n,vector<int>(n,0));
        for(i=0;i<n;i++)
        {
            first[i][i]=A[i];
            second[i][i]=0;
            for(j=i-1;j>=0;j--)
            {
                first[j][i]=((A[j]+second[j+1][i])>=(A[i]+second[j][i-1]))?(A[j]+second[j+1][i]):(A[i]+second[j][i-1]);
                second[j][i]=(first[j+1][i]<=first[j][i-1])?first[j+1][i]:first[j][i-1];
            }
        }
        res=(first[0][n-1]>=second[0][n-1])?first[0][n-1]:second[0][n-1];
        return res;
    }
};