201609-5 祭坛

超时暴力60分

#include <iostream>
#include <algorithm>
#include <cstring>
#include <sstream>
using namespace std;
typedef long long LL;
const int N = 5e5 + 4, mod = 1e9 + 7;

vector<int> v[N];
int y[N], sizy, x[N], sizx, numx[N], a[N], b[N], n, q;
int c[N];

// 这题暴力就是 先离散化之后看每个网格交点是否满足；
// 优化就是区间的时候可以先求出最大值，再一遍线段树更新每个点是否满足，修改是单点修改，查询是区间和 

int main() 
{
	scanf("%d%d", &n, &q);
	for(int i = 1;i <= n;i ++)
	{
		scanf("%d%d", a+i, b+i);
		y[i] = a[i]; x[i] = b[i];  // 离散化数组，y和x好像有点抽象 
	}
	sort(y+1, y+n+1); sizy = unique(y+1, y+n+1)-y;
	sort(x+1, x+n+1); sizx = unique(x+1, x+n+1)-x;
	for(int i = 1;i <= n;i ++)
	{
		a[i] = lower_bound(y+1, y+sizy, a[i]) - y;
		b[i] = lower_bound(x+1, x+sizx, b[i]) - x; numx[b[i]] ++;
		v[a[i]].push_back(b[i]);  
	}
	for(int i = 1;i <= sizy;i ++)
		sort(v[i].begin(), v[i].end());

	int ma = 0, ans = 0;
	for(int i = 1;i < sizy;i ++)
	{
		for(int j = 0;j < v[i].size()-1;j ++)
			for(int t = v[i][j]+1;t < v[i][j+1];t ++)   // 遍历每个点算答案 
			{
				int mi = min(min(c[t], numx[t]-c[t]), min(j+1, (int)v[i].size()-j-1));
				if(mi>ma)  // 更新答案 
					ma = mi, ans = 1;  
				else if(ma == mi)
					ans ++;
			}
		for(auto x:v[i])
			c[x] ++;		
	}
	if(q-1)cout<<ans;
	else cout<<ma;
	puts("");
	return 0;
}

100分线段树单点修改代码

#include <iostream>
#include <algorithm>
#include <cstring>
#include <sstream>
#define ls  (u<<1)
#define rs  (u<<1|1)
#define mid (l+r>>1)
using namespace std;
typedef long long LL;
const int N = 3e5 + 4, mod = 1e9 + 7;

vector<int> v[N];
int y[N], sizy, x[N], sizx, numx[N], a[N], b[N], n, q;
int c[N], ma = 0;
LL ans = 0;
struct point{
	int ma, sum;
}tr[N<<2];

void push_up(point &a, point &b, point &c){a.sum = b.sum+c.sum;a.ma=max(b.ma,c.ma);return ;}

void modify(int u, int l, int r, int x, int f)
{
	if(l==r){
		tr[u].ma = min(c[x], numx[x]-c[x]);
		if(f)   // 这个要判断，因该是 又一遍开始的时候有答案贡献把，奇怪； 
			tr[u].sum = tr[u].ma >= ma ;	
	}
	else {
		x <= mid ? modify(ls, l, mid, x, f) : modify(rs, mid+1, r, x, f);
		push_up(tr[u], tr[ls], tr[rs]);
	}
	return ;
}

point quary(int u, int l, int r, int L, int R)
{	
	if(L<=l&&R>=r) return tr[u];
	point x = {0, 0}, z = {0, 0}, y = {0, 0};
	if(L <= mid) y = quary(ls, l, mid, L, R);
	if(R > mid) z = quary(rs, mid+1, r, L, R);
	push_up(x, z, y);
	return x; 	
}

int main() 
{
	scanf("%d%d", &n, &q);
	for(int i = 1;i <= n;i ++)
	{
		scanf("%d%d", a+i, b+i);
		y[i] = a[i]; x[i] = b[i];
	}
	sort(y+1, y+n+1); sizy = unique(y+1, y+n+1)-y;
	sort(x+1, x+n+1); sizx = unique(x+1, x+n+1)-x;
	for(int i = 1;i <= n;i ++)
	{
		a[i] = lower_bound(y+1, y+sizy, a[i]) - y;
		b[i] = lower_bound(x+1, x+sizx, b[i]) - x; numx[b[i]] ++;
		v[a[i]].push_back(b[i]);  
	}
	for(int i = 1;i <= sizy;i ++)
		sort(v[i].begin(), v[i].end());

	for(int i = 1;i < sizy;i ++)
	{
		for(int j = 0;j < v[i].size()-1;j ++)
			if(v[i][j]+1 < v[i][j+1])
			{
				int mi = min(min(j+1, (int)v[i].size()-j-1), quary(1, 1, sizx, v[i][j]+1, v[i][j+1]-1).ma);
				if(mi>ma) 
					ma = mi; 
			}
		for(auto x:v[i])
			c[x] ++, modify(1, 1, sizx, x, 0);
	}
	
	for(int i = 1;i < sizx;i ++) c[i] = 0;
	for(int i = 1;i < sizy;i ++)
	{
		for(int j = 0;j < v[i].size()-1;j ++)
			if(v[i][j]+1 < v[i][j+1])
				ans += quary(1, 1, sizx, v[i][j]+1, v[i][j+1]-1).sum;
				
		for(auto x:v[i])
			c[x] ++, modify(1, 1, sizx, x, 1);
	}
	if(ma == 0)ans = 0;
	if(q&1)cout<<ma;
	else cout<<ans;
	puts("");
	return 0;
}