11572 Unique snowflakes

代码:

#include<cstdio>

#include<set>

#include<algorithm>

usingnamespace std;



constint maxn = 1000000 + 5;

intA[maxn];



intmain()

{

int T, n;

scanf("%d", &T);

while(T--)

{

scanf("%d", &n);

for(int i = 0; i < n; i++)

{

scanf("%d", &A[i]);

}

set<int> s;

int L = 0, R = 0, ans = 0;

while(R < n)

{

while(R < n &&!s.count(A[R]))

{

s.insert(A[R++]);

}

ans = max(ans, R - L);

s.erase(A[L++]);

}

printf("%d\n", ans);

}

return 0;

}

set中的查找很快。