LeetCode1124. Longest Well-Performing Interval

一、题目

We are given hours, a list of the number of hours worked per day for a given employee.

A day is considered to be a tiring day if and only if the number of hours worked is (strictly) greater than 8.

A well-performing interval is an interval of days for which the number of tiring days is strictly larger than the number of non-tiring days.

Return the length of the longest well-performing interval.

Example 1:

Input: hours = [9,9,6,0,6,6,9]
Output: 3
Explanation: The longest well-performing interval is [9,9,6].
Example 2:

Input: hours = [6,6,6]
Output: 0

Constraints:

1 <= hours.length <= 104
0 <= hours[i] <= 16

二、题解

class Solution {
public:
    int longestWPI(vector<int>& hours) {
        int n = hours.size();
        unordered_map<int,int> map;
        int res = 0,sum = 0;
        map[0] = -1;
        for(int i = 0;i < n;i++){
            hours[i] > 8 ? sum += 1 : sum += -1;
            if(sum > 0) res = i + 1;
            else{
                if(map.find(sum-1) != map.end()){
                    res = max(res,i-map[sum-1]);
                }
            }
            if(map.find(sum) == map.end()) map[sum] = i;
        }
        return res;
    }
};