[数组] leetcode 565 Array Nesting

problem:https://leetcode.com/problems/array-nesting/

       这道题有点类似于找最大的连通子图，只不过是以数组来表示的，难度并不高。

class Solution {
public:
    int arrayNesting(vector<int>& nums) {
        vector<bool> visit(nums.size(),false);
        int res = 0;
        for(int i = 0;i < nums.size();i++)
        {
            int count = 1;
            int j = i;
            visit[j] = true;
            while(!visit[nums[j]])
            {
                count++;
                visit[nums[j]] = true;
                j = nums[j];
            }
           // cout << count << " ";
            res = max(count, res);
        }
        return res;
    }
};