【luogu P3369 【模板】普通平衡树（Treap/SBT）】 题解 pb_ds

我永远都爱STL ! 我爱PB_DS !

#include <iostream>
#include <cstdio>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
typedef long long ll;
tree<ll,null_type,std::less<ll>,splay_tree_tag,tree_order_statistics_node_update> st;
int main()
{
	int m;
	ll ans, x, y;
	scanf("%d",&m);
	for(int i = 1; i <= m; i++)
	{
		scanf("%lld%lld",&x,&y);
		if(x == 1) st.insert((y<<20)+i);
		else if(x == 2) st.erase(st.lower_bound(y<<20));
		else if(x == 3) printf("%d\n",st.order_of_key(y<<20)+1);
		else {
			if(x == 4) ans = *st.find_by_order(y-1);
			if(x == 5) ans = *--st.lower_bound(y<<20);
			if(x == 6) ans = *st.lower_bound((y+1)<<20);
			printf("%lld\n",ans>>20);
		}
	}
	return 0;
}

其实还可以用set，vector做...
我永远都喜欢stl