LeetCode 1014. 最佳观光组合

示例：
输入：[8,1,5,2,6]
输出：11
解释：i = 0, j = 2, A[i] + A[j] + i - j = 8 + 5 + 0 - 2 = 11
 
提示：
2 <= A.length <= 50000
1 <= A[i] <= 1000

class Solution {
public:
    int maxScoreSightseeingPair(vector<int>& A) {
        int i, j, scores = 0;
        for(i = 0; i < A.size(); ++i)
        {
        	for(j = i+1; j < A.size(); ++j)
        		scores = max(scores, A[i]+A[j]+i-j);
        }
        return scores;
    }
};

class Solution {
public:
    int maxScoreSightseeingPair(vector<int>& A) {
        int i, scoresA = A[0]+0, scores = 0;
        for(i = 1; i < A.size(); ++i)
        {
        	scores = max(scores, scoresA + A[i]-i);//历史的A的得分，当前的B得分
        	scoresA = max(scoresA, A[i]+i); //记录最大的A点得分
        }
        return scores;
    }
};