[leetcode]697. Degree of an Array

[leetcode]697. Degree of an Array

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Analysis

一个有台风的周末~—— [中午吃什么外卖呢~]

Given a non-empty array of non-negative integers nums, the degree of this array is defined as the maximum frequency of any one of its elements.

Your task is to find the smallest possible length of a (contiguous) subarray of nums, that has the same degree as nums.

Implement

class Solution {
public:
    int findShortestSubArray(vector<int>& nums) {
        unordered_map<int, int> has, index;
        int res = INT_MAX;
        int degree = 0;
        int len = nums.size();
        for(int i=0; i<len; i++){
            if(!has.count(nums[i]))
                index[nums[i]] = i;
            has[nums[i]]++;

            if(has[nums[i]] == degree)
                res = min(res, i-index[nums[i]]+1);
            else if(has[nums[i]] > degree){
                degree = has[nums[i]];
                res = i - index[nums[i]] + 1;
            }
        }
        return res;
    }
};