classSolution{public:intlongestConsecutive(vector<int>& nums){// 去重// 判断每个数是否为序列开头,如果不是就跳过,如果是就往后遍历直到序列结束
unordered_set<int>sets;for(auto it : nums){
sets.insert(it);}int ret =0;for(auto it : sets){if(!sets.count(it -1)){// 是开头,往后遍历int t =1;while(sets.count(it +1)){
it++;
t++;}
ret =max(ret, t);}}return ret;}};