BZOJ 2738 矩阵乘法

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define maxn 250050
using namespace std;
struct pnt
{
int x,y,val;
}p[maxn];
struct query
{
int x1,y1,x2,y2,id,k;
}q[maxn];
int n,m,x,t[550][550],cnt=0,ans[maxn],id[maxn],mx=0,T=0,tmp[maxn];
bool vis[maxn];
bool cmp(pnt x,pnt y)
{
return x.val<y.val;
}
int lowbit(int x) {return (x&(-x));}
void add(int x,int y,int val)
{
for (int i=x;i<=n;i+=lowbit(i))
for (int j=y;j<=n;j+=lowbit(j))
t[i][j]+=val;
}
int ask(int x,int y)
{
int ret=0;
for (int i=x;i>=1;i-=lowbit(i))
for (int j=y;j>=1;j-=lowbit(j))
ret+=t[i][j];
return ret;
}
int find(int x)
{
return ask(q[x].x2,q[x].y2)-ask(q[x].x1-1,q[x].y2)-ask(q[x].x2,q[x].y1-1)+ask(q[x].x1-1,q[x].y1-1);
}
void solve(int l,int r,int L,int R)
{
if (l==r) return;
if (L>R) return;
int mid=l+r>>1,l1,l2,ret=0;
while ((p[T+1].val<=mid) && (T<cnt)) {add(p[T+1].x,p[T+1].y,1);T++;}
while ((p[T].val>mid) && (T>=1)) {add(p[T].x,p[T].y,-1);T--;}
for (int i=L;i<=R;i++)
{
int now=find(id[i]);
if (now>q[id[i]].k-1) {vis[i]=true;ans[id[i]]=mid;ret++;}
else vis[i]=false;
}
l1=L;l2=L+ret;
for (int i=L;i<=R;i++)
{
if (vis[i]) tmp[l1++]=id[i];
else tmp[l2++]=id[i];
}
for (int i=L;i<=R;i++) id[i]=tmp[i];
solve(l,mid,L,l1-1);solve(mid+1,r,l1,l2-1);
}
int main()
{
scanf("%d%d",&n,&m);
for (int i=1;i<=n;i++)
for (int j=1;j<=n;j++)
{
scanf("%d",&x);
cnt++;mx=max(mx,x);
p[cnt].x=i;p[cnt].y=j;p[cnt].val=x;
}
sort(p+1,p+cnt+1,cmp);
for (int i=1;i<=m;i++)
{
scanf("%d%d%d%d%d",&q[i].x1,&q[i].y1,&q[i].x2,&q[i].y2,&q[i].k);
q[i].id=i;
}
for (int i=1;i<=m;i++) id[i]=i;
solve(0,mx+1,1,m);
for (int i=1;i<=m;i++) printf("%d\n",ans[i]);
return 0;
}