题目技巧:滑动窗口
题目链接:https://leetcode-cn.com/contest/biweekly-contest-3/problems/find-k-length-substrings-with-no-repeated-characters/
代码:
假定一个窗口往右滑动,用queue来保存窗口元素的顺序,用set来查重
class Solution {
public:
int numKLenSubstrNoRepeats(string S, int K) {
set<char> window;
queue<char> que;
int coun = 0;
for(int i = 0;i<S.length();i++){
if(window.find(S[i]) == window.end()){
window.insert(S[i]);
que.push(S[i]);
while(que.size() > K){
window.erase(que.front());
que.pop();
}
} else{
while(que.front() != S[i]){
window.erase(que.front());
que.pop();
}
window.erase(que.front());
que.pop();
window.insert(S[i]);
que.push(S[i]);
}
if(que.size() == K && window.size() == K){
coun++;
}
}
return coun;
}
};