class Solution {
public:
/**
*
* @param arr int整型vector the array
* @return int整型
*/
int maxLength(vector<int>& arr) {
// write code here
int len = arr.size();
int ret = 0, start = 0;
map<int, int>mp;
for (int i = 0; i < len; i++) {
// 如果找到重复的,开始刷新ret
if(mp.find(arr[i]) != mp.end()) {
start = max(start, mp[arr[i]] + 1);
}
ret = max(ret, i - start + 1);
// 更新位置
mp[arr[i]] = i;
}
return ret;
}
};