Uva - 11572 - Unique Snowflakes

来源：互联网发布：java软件开发培训学校编辑：程序博客网时间：2024/05/22 13:13

从左往右延伸，用一个set存储当前序列，向右延伸的时候如果元素已经在set中存在，则增大左边界；如果不存在，则把新增右边界的元素放到set中。

AC代码：

#include <iostream>#include <cstdio>#include <cstdlib>#include <cctype>#include <cstring>#include <string>#include <sstream>#include <vector>#include <set>#include <map>#include <algorithm>#include <stack>#include <queue>#include <bitset> #include <cassert> #include <cmath>using namespace std;const int maxn = 1000005;int snowflakes[maxn];int main(){<span style="white-space:pre"></span>ios::sync_with_stdio(false);<span style="white-space:pre"></span>int T;<span style="white-space:pre"></span>cin >> T;<span style="white-space:pre"></span>while (T--) {<span style="white-space:pre"></span>int n;<span style="white-space:pre"></span>cin >> n;<span style="white-space:pre"></span>for (int i = 0; i < n; i++) {<span style="white-space:pre"></span>cin >> snowflakes[i];<span style="white-space:pre"></span>}<span style="white-space:pre"></span>// 存放当前序列的所有元素<span style="white-space:pre"></span>set<int> s;<span style="white-space:pre"></span>int letfP = 0, rightP = 0, ans = 0;<span style="white-space:pre"></span>while (rightP < n) {<span style="white-space:pre"></span>while (rightP < n && !s.count(snowflakes[rightP])) {<span style="white-space:pre"></span>s.insert(snowflakes[rightP++]);<span style="white-space:pre"></span>}<span style="white-space:pre"></span>ans = max(ans, rightP - letfP);<span style="white-space:pre"></span>s.erase(snowflakes[letfP++]); // 增大左边界<span style="white-space:pre"></span>}<span style="white-space:pre"></span>cout << ans << endl;<span style="white-space:pre"></span>}<span style="white-space:pre"></span>return 0;}

0 0