SuperMemo POJ3580_poj3580超时-优快云博客

本文链接：https://blog.youkuaiyun.com/gyarenas/article/details/9235775

本文深入探讨数据结构和算法的优化策略，包括排序、动态规划、哈希算法等核心概念，通过实例演示如何提高程序效率，实现复杂度降低。

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数据比较恶心的一道题，主要是REVOLVE的数据可以超过长度，而且还可能是负数，爱神的思路比较巧妙，利用模代数系统各种数据都等价到[0, len-1]，这样就可以很方便的处理了。

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <algorithm>
#include <vector>
#include <cstring>
#include <stack>
#include <cctype>
#include <utility>   
#include <map>
#include <string>  
#include <climits> 
#include <set>
#include <string>    
#include <sstream>
#include <utility>   
#include <ctime>

using std::priority_queue;
using std::vector;
using std::swap;
using std::stack;
using std::sort;
using std::max;
using std::min;
using std::pair;
using std::map;
using std::string;
using std::cin;
using std::cout;
using std::set;
using std::queue;
using std::string;
using std::istringstream;
using std::make_pair;
using std::getline;
using std::greater;
using std::endl;
using std::multimap;
using std::deque;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> PAIR;
typedef multimap<int, int> MMAP;

const int MAXN(200010);
const int MAXM(10010);
const int MAXE(10010);
const int MAXH(19);
const int INFI((INT_MAX-1) >> 1);
const int MOD(10000);
const ULL BASE(31);
const LL LIM(10000000);
const int INV(-10000);


int arr[MAXN];

struct SPLAY_TREE
{
	struct NODE
	{
		int num, size, flag1, flag2;  
		int mi;
		NODE *fa;
		NODE *ch[2];
	};

	NODE pool[MAXN];
	NODE *root, *NIL, *rear;
	inline void push_up(NODE *sour)  //一定要注意NIL节点对push_up的影响
	{
		sour->size = sour->ch[0]->size+sour->ch[1]->size+1;
		sour->mi = min(sour->num, min(sour->ch[0]->mi, sour->ch[1]->mi));
	}
	inline void updata_add(NODE *sour, int v)
	{
		if(sour == NIL) return;
		sour->mi += v;
		sour->num += v;
		sour->flag1 += v;
	}
	inline void updata_rev(NODE *sour)
	{
		if(sour == NIL) return;
		swap(sour->ch[0], sour->ch[1]);
		sour->flag2 ^= 1;
	}
	void push_down(NODE *sour)  //和线段树的push_down一样，是对子节(注意不是本节点)进行更新
	{
		if(sour->flag1)
		{
			updata_add(sour->ch[0], sour->flag1);
			updata_add(sour->ch[1], sour->flag1);
			sour->flag1 = 0;
		}
		if(sour->flag2)
		{
			updata_rev(sour->ch[0]);
			updata_rev(sour->ch[1]);
			sour->flag2 = 0;
		}
	}
	void initNIL()
	{
		NIL->ch[0] = NIL->ch[1] = NIL->fa = NIL;
		NIL->mi = INFI;
		NIL->size = 0;
	}

	void init(int n)
	{
		NIL = pool;
		initNIL();
		rear = pool+1;
		newnode(root, NIL, -100000);  //插入无穷小
		newnode(root->ch[1], root, 100000); //插入无穷大
		build_tree(root->ch[1]->ch[0], root->ch[1], 1, n); //建树
		push_up(root->ch[1]);
		push_up(root);
	}

	void newnode(NODE *&sour, NODE *f, int num)
	{
		sour = rear++;
		sour->num = sour->mi = num;
		sour->size = 1;
		sour->flag1 = sour->flag2 = 0;
		sour->fa = f;
		sour->ch[0] = sour->ch[1] = NIL;
	}

	void build_tree(NODE *&sour, NODE *f, int l, int r)
	{
		if(l > r)
			return;
		int m = (l+r) >> 1;
		newnode(sour, f, arr[m]);
		build_tree(sour->ch[0], sour, l, m-1);
		build_tree(sour->ch[1], sour, m+1, r);
		push_up(sour);
	}

	void rotate(NODE *sour, int flag)
	{
		NODE *f = sour->fa;
		push_down(f);
		push_down(sour);
		f->ch[!flag] = sour->ch[flag];
		sour->ch[flag]->fa = f;
		sour->fa = f->fa;
		if(f->fa != NIL)
			f->fa->ch[f->fa->ch[1] == f] = sour;
		sour->ch[flag] = f;
		f->fa = sour;
		push_up(f);
	}
	
	void splay(NODE *sour, NODE *goal)
	{
		push_down(sour);
		while(sour->fa != goal)
		{
			if(sour->fa->fa == goal)
				rotate(sour, sour->fa->ch[0] == sour);
			else
			{
				NODE *f = sour->fa;
				int flag = (f->fa->ch[0] == f);
				if(f->ch[flag] == sour)
					rotate(sour, !flag);
				else
					rotate(f, flag);
				rotate(sour, flag);
			}
		}
		push_up(sour);
		if(goal == NIL)
			root = sour;
	}

	NODE *select(NODE *sour, int r)
	{
		while(true)
		{
			push_down(sour);
			if(r == sour->ch[0]->size+1)
				break;
			if(r <= sour->ch[0]->size)
				sour = sour->ch[0];
			else
			{
				r -= sour->ch[0]->size+1;
				sour = sour->ch[1];
			}
		}
		return sour;
	}
	
	void ADD(int pos1, int pos2, int value)
	{
		NODE *tp;
		tp = select(root, pos1);
		splay(tp, NIL);
		tp = select(root, pos2+2);
		splay(tp, root);
		updata_add(tp->ch[0], value);
		push_up(root->ch[1]);
		push_up(root);
	}

	void REVERSE(int pos1, int pos2)
	{
		NODE *tp;
		tp = select(root, pos1);
		splay(tp, NIL);
		tp = select(root, pos2+2);
		splay(tp, root);
		updata_rev(tp->ch[0]);
		push_up(root->ch[1]);
		push_up(root);
	}

	void REVOLVE(int pos1, int pos2, int T)
	{
		NODE *tp1, *tp2;
		tp1 = select(root, pos1);
		splay(tp1, NIL);
		tp1 = select(root, pos2-T+2);
		splay(tp1, root);
		tp2 = tp1->ch[0];
		tp1->ch[0] = NIL;
		push_up(root->ch[1]);
		push_up(root);
		tp1 = select(root, pos1+T);
		splay(tp1, NIL);
		tp1 = select(root, pos1+T+1);
		splay(tp1, root);
		tp1->ch[0] = tp2;
		tp2->fa = tp1;
		push_up(root->ch[1]);
		push_up(root);
	}

	void INSERT(int pos, int value)
	{
		NODE *tp;
		tp = select(root, pos+1);
		splay(tp, NIL);
		tp = select(root, pos+2);
		splay(tp, root);
		newnode(tp->ch[0], tp, value);
		push_up(root->ch[1]);
		push_up(root);
	}

	void DELETE(int pos)
	{
		NODE *tp;
		tp = select(root, pos);
		splay(tp, NIL);
		tp = select(root, pos+2);
		splay(tp, root);
		tp->ch[0] = NIL;
		push_up(root->ch[1]);
		push_up(root);
	}

	int MIN(int pos1, int pos2)
	{
		NODE *tp;
		tp = select(root, pos1);
		splay(tp, NIL);
		tp = select(root, pos2+2);
		splay(tp, root);
		return tp->ch[0]->mi;
	}
};

SPLAY_TREE spt;
char str[10];

int main()
{
	int n;
	while(~scanf("%d", &n))
	{
		for(int i = 1; i <= n; ++i)
			scanf("%d", arr+i);
		spt.init(n);
		int m;
		scanf("%d", &m);
		int op1, op2, op3;
		for(int i = 0; i < m ; ++i)
		{
			scanf("%s", str);
			if(str[0] == 'A')
			{
				scanf("%d%d%d", &op1, &op2, &op3);
				spt.ADD(op1, op2, op3);
			}
			else if(str[0] == 'R' && str[3] == 'E')
			{
				scanf("%d%d", &op1, &op2);
				spt.REVERSE(op1, op2);
			}
			else if(str[0] == 'R' && str[3] == 'O')
			{
				scanf("%d%d%d", &op1, &op2, &op3);
				int tlen = op2-op1+1;
				spt.REVOLVE(op1, op2, (op3%tlen+tlen)%tlen);
			}
			else if(str[0] == 'I')
			{
				scanf("%d%d", &op1, &op2);
				spt.INSERT(op1, op2);
			}
			else if(str[0] == 'D')
			{
				scanf("%d", &op1);
				spt.DELETE(op1);
			}
			else
			{
				scanf("%d%d", &op1, &op2);
				printf("%d\n", spt.MIN(op1, op2));
			}
		}
	}
	return 0;
}