UVa #11572 Unique Snowflakes (例题8-7)

给出一个序列，要求找出一个最长的连续子序列，使得这个子序列中没有重复的元素。

连续、子序列、不重复，这些关键词都指向滑动窗口

用STL的set和map都会比较慢，我觉得自己写hash会快一些。以后有机会再回来写hash版的吧

Run Time: 1.032s

#define UVa  "LT8-7.11572.cpp"#include<cstdio>#include<vector>#include<cstring>#include<algorithm>#include<map>using namespace std;int main() {    int T, n;    scanf("%d", &T);    for(int kase = 1; kase <= T; kase ++) {        vector<long long> snowflakes;        scanf("%d", &n);        long long tmp;        for(int i = 0; i < n; i ++) {            scanf("%lld", &tmp);            snowflakes.push_back(tmp);        }        map<long long, int> uniq;        int l = 0, r = 0;        int maxsize = 1;        while(r < n) {            int u = snowflakes[r];            if(uniq.count(u) && uniq[u] >= l && uniq[u] < r) {        //repeated in current range.                l = uniq[u] + 1;            }            uniq[u] = r;            maxsize = max(maxsize, r - l + 1);            r++;        }        printf("%d\n", maxsize);    }    return 0;}