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特定n一个操作，m长序列a

下列n的数量

if(co>=0)向字符串加入一个co （開始是空字符串）

else 删除字符串中有a的下标的字符

直接在序列上搞。简单模拟

#include<stdio.h>

#include<iostream>

#include<string.h>

#include<set>

#include<vector>

#include<map>

#include<math.h>

#include<string>

#include<stdlib.h>

#include<algorithm>

using namespace std;

#define N 1000005

bool use[N], b[N];

int top;

int n, m;

int a[N];

int c[N], maxn;

inline int lowbit(int x){return x&(-x);}

void change(int pos, int val){

	while(pos<=maxn){

		c[pos]+=val;

		pos+=lowbit(pos);

	}

}

int sum(int pos){

	int ans = 0;

	while(pos)ans+=c[pos], pos-=lowbit(pos);

	return ans;

}

set<int>myset;

set<int>::iterator p;

void Erase(int pos, int r){

	int l = 1;

	while(l<=r) {

		int mid = (l+r)>>1;

		int tmp = sum(mid);

		if(tmp==pos) {

			p = myset.upper_bound(mid);

			p--;

			mid = *p;

			change(mid, -1);

			use[mid] = 1;

			myset.erase(p);

			return ;

		}

		if(tmp>pos) r = mid-1;

		else l = mid+1;

	}

}

void init(){myset.clear(); memset(c, 0, sizeof c); maxn = n+10; top = 0;}

int main(){

	int i,j,co;

	while(~scanf("%d %d",&n,&m)){

		init();

		for(i=0;i<m;i++)scanf("%d",&a[i]);

		int len = 0;

		for(i = 1; i <= n; i++) {

			scanf("%d",&co);

			if(co>=0)

				use[i] = 0, b[i] = co, change(i,1), len++, myset.insert(i);

			else {

				use[i] = 1;

				int j = lower_bound(a, a+m, len) - a;

				if(j==0 && len<a[0])continue;

				if(len!=a[j])j--;

				while(j>=0) {

					Erase(a[j], i);

					j--;

					len--;

				}

			}

		}

		if(!len)puts("Poor stack!");

		else {

			for(i = 1; i <= n; i++) if(!use[i])

				printf("%d",b[i]);

			puts("");

		}

	}

	return 0;

}