Leetcode[219]-Contains Duplicate II

Given an array of integers and an integer k, find out whether there there are two distinct indices i and j in the array such that nums[i] = nums[j] and the difference between i and j is at most k.

分析：用map记录num和下标value，遍历数组，如果在map中存在
【mapv.find(number) != mapv.end()】并且当前位置和map中找到的位置差小于等于k【i-mapv[number] <= k】，就返回true，不然就将该值加入到map中。依次循环…

Code(c++)

class Solution {  
public:  
    bool containsNearbyDuplicate(vector<int>& nums, int k) {
        int n = nums.size();
        map<int, int> mapv;
        for (int i = 0; i < n; i++){
            int number = nums[i];
            if (mapv.find(number) != mapv.end() && i-mapv[number] <= k){
                return true;
            }else{
                mapv[number] = i;
            }
        }
        return false;
    }
};