表现良好的最长时间段

Leetcode题目链接

描述

详见中文题目链接。

解答

class Solution {
public:
    int longestWPI(vector<int>& hours) {
        unordered_map<int, int> prefixMap;
        prefixMap[0] = -1;
        int res = 0;

        for (int i = 0, sum = 0; i < hours.size(); i++) {
            sum += hours[i] > 8 ? 1 : -1;
            if (sum > 0) {
                res = i + 1;
            } else {
                if (prefixMap.find(sum - 1) != prefixMap.end()) {
                    res = max(res, i - prefixMap[sum - 1]);
                }
            }

            if (prefixMap.find(sum) == prefixMap.end()) {
                prefixMap[sum] = i;
            }
        }

        return res;
    }
};