牛客暑假多校第二场J-farm

一、题意

White Rabbit has a rectangular farmland of n*m. In each of the grid there is a kind of plant. The plant in the j-th column of the i-th row belongs the a[i][j]-th type.
White Cloud wants to help White Rabbit fertilize plants, but the i-th plant can only adapt to the i-th fertilizer. If the j-th fertilizer is applied to the i-th plant (i!=j), the plant will immediately die.
Now White Cloud plans to apply fertilizers T times. In the i-th plan, White Cloud will use k[i]-th fertilizer to fertilize all the plants in a rectangle [x1[i]...x2[i]][y1[i]...y2[i]].
White rabbits wants to know how many plants would eventually die if they were to be fertilized according to the expected schedule of White Cloud.
简单的说就是,给定一个大型矩形,矩形中每个格子对应一个单独的数字。之后K个命令给,要求大矩阵中某些子矩形的各个元素的赋予统一值,求在命令结束后还保持原有值的个数。其中矩阵的格子总数不超过1e6,但是不指定长宽。

二、解题思路

要求使用一种数据结构进行批量染色操作,且要求后面可以检测是否被"其他颜色污染"。

看了题解很容易想到,使用某种数据结构做批量增加的操作,之后检测增加后的值是否能够整除原来的元素。

考虑如果直接按照1、2、3、4进行赋值就会有:同样是染色2次,有3+3 = 6和2+2+2 = 6,无法有效判断整除。考虑加一个操作:增加染色次数的判定,但是同样也会有3+3 = 6 = 2+4的问题,因此对数组进行重新设计,则直觉告诉我们,1,2,4,7,......an,an+n这个数列可以完美解决这个问题——不存在第2种组合可以使用相同数目的数列元素相加得到数列的某个其他元素。

因此,使用一位数组开足够大的数组之后,动态的按照二维数组的方式进行寻址,即可完成上述操作。

#include<bits/stdc++.h>
using namespace std; #define ll intmax_t const int MAXN=; ll mapp[MAXN];
ll farm[MAXN];
ll times[MAXN];
ll color[MAXN]; int maxx_numebr = ;
int add_number = ; int m,n,k; void insert_mex(ll *v,int a,int b,ll key)
{
a+=;
b+=;
while(a<n+)
{
int num = a*(m+);
int pos = b;
while(pos<m+)
{
v[num+pos] += key;
pos+= pos&(-pos);
}a+=a&(-a); }
}
ll find_mex(ll *v,int a,int b)
{
a+=;
b+=;
ll cntt = ;
while(a)
{
int num = a*(m+);
int pos = b;
while(pos)
{
cntt += v[num+pos];
pos -= pos&(-pos);
}
a-=a&(-a);
}
return cntt;
} void insert(ll *v,int a,int b,int c,int d,ll key)
{
// cout<<"coor :"<<a<<" "<<b<<endl;
// cout<<"coor :"<<a<<" "<<d<<endl;
// cout<<"coor :"<<c<<" "<<b<<endl;
// cout<<"coor :"<<c<<" "<<d<<endl; insert_mex(v,a,b,key);
insert_mex(v,c,d,key);
insert_mex(v,a,d,-key);
insert_mex(v,c,b,-key);
} ll find(ll *v,int a,int b)
{
ll cntt = ;
cntt += find_mex(v,a,b);
return cntt;
} void init()
{
memset(color,-,sizeof(color));
for(int i=;i<n;++i)
{
int pos = i*m;
for(int j=;j<m;++j)
{
// int ppos = pos +j;
scanf("%d",&mapp[pos]);
if(color[pos] == -)color[mapp[pos]] = (maxx_numebr += (add_number++));
pos++;
}
}
for(int i=;i<k;++i)
{
int a,b,c,d,kk;
scanf("%d%d%d%d%d",&a,&b,&c,&d,&kk);
if(color[kk] == -)color[kk] = (maxx_numebr += add_number++ );
ll key = color[kk];
a--;b--;
insert(farm,a,b,c,d,key);
insert(times,a,b,c,d,);
}
int cntt = n*m;
int pos = ;
for(int i=;i<n;++i)
{
for(int j=;j<m;++j)
{
// int pos = i*(m+23)+j;
ll kk = color[mapp[pos]];
int time_now = find(times,i,j);
ll res = find(farm,i,j);
// cout<<"check: "<<i<<" "<<j<<" times: "<<time_now<<" color "<<mapp[pos]<<endl;
if(time_now == || res == time_now*kk)cntt--;
pos++;
}
}
cout<<cntt<<endl; } int main()
{
cin>>n>>m>>k;
init(); return ;
}
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