二维线段树（Mosaic，hdu 4819）

来源：互联网发布：linux shell cut 编辑：程序博客网时间：2024/05/16 10:04
参考代码：http://www.cnblogs.com/Wine93/p/3515756.html
就是裸的二维线段树
代码
#include<bits/stdc++.h>#define maxn 850using namespace std;int n;int Q,x,y,l;int xl,xr,yl,yr;int ansmin,ansmax,ans;int a[maxn][maxn];int MIN[maxn<<2][maxn<<2];int MAX[maxn<<2][maxn<<2];void PushUpY(int xnow,int ynow){    MIN[xnow][ynow]=min(MIN[xnow][ynow<<1],MIN[xnow][ynow<<1|1]);    MAX[xnow][ynow]=max(MAX[xnow][ynow<<1],MAX[xnow][ynow<<1|1]);}void PushUpX(int xnow,int ynow){    MIN[xnow][ynow]=min(MIN[xnow<<1][ynow],MIN[xnow<<1|1][ynow]);    MAX[xnow][ynow]=max(MAX[xnow<<1][ynow],MAX[xnow<<1|1][ynow]);}void BUILDY(int xnow,int x,int key,int l,int r,int now){    if(l==r)    {        if(key) MIN[xnow][now]=MAX[xnow][now]=a[x][l];        else PushUpX(xnow,now);        return;    }    int m=l+(r-l)/2;    BUILDY(xnow,x,key,l,m,now<<1);    BUILDY(xnow,x,key,m+1,r,now<<1|1);    PushUpY(xnow,now);}void BUILDX(int l,int r,int now){    if(l==r)    {        BUILDY(now,l,1,1,n,1);        return;    }    int m=l+(r-l)/2;    BUILDX(l,m,now<<1);    BUILDX(m+1,r,now<<1|1);    BUILDY(now,l,0,1,n,1);}void QueryY(int xnow,int l,int r,int now){    if(yl<=l&&r<=yr)    {        ansmax=max(ansmax,MAX[xnow][now]);        ansmin=min(ansmin,MIN[xnow][now]);        return;    }    int m=l+(r-l)/2;    if(yl<=m) QueryY(xnow,l,m,now<<1);    if(yr>m) QueryY(xnow,m+1,r,now<<1|1);}void QueryX(int l,int r,int now){    if(xl<=l&&r<=xr)    {        QueryY(now,1,n,1);        return;    }    int m=l+(r-l)/2;    if(xl<=m) QueryX(l,m,now<<1);    if(xr>m) QueryX(m+1,r,now<<1|1);}void UpDataY(int xnow,int key,int l,int r,int now){    if(l==r)    {        if(key) MAX[xnow][now]=MIN[xnow][now]=a[x][y]=ans;        else PushUpX(xnow,now);        return;    }    int m=l+(r-l)/2;    if(y<=m) UpDataY(xnow,key,l,m,now<<1);    else UpDataY(xnow,key,m+1,r,now<<1|1);    PushUpY(xnow,now);}void UpDataX(int l,int r,int now){    if(l==r)    {        UpDataY(now,1,1,n,1);        return;    }    int m=l+(r-l)/2;    if(x<=m) UpDataX(l,m,now<<1);    else UpDataX(m+1,r,now<<1|1);    UpDataY(now,0,1,n,1);}int main(){    int T;    scanf("%d",&T);    for(int t=1;t<=T;t++)    {        printf("Case #%d:\n",t);        scanf("%d",&n);        for(int i=1;i<=n;i++)            for(int j=1;j<=n;j++)                scanf("%d",&a[i][j]);        BUILDX(1,n,1);        scanf("%d",&Q);        while(Q--)        {            scanf("%d %d %d",&x,&y,&l);            l/=2;            xl=max(1,x-l);xr=min(n,x+l);            yl=max(1,y-l);yr=min(n,y+l);            ansmin=INT_MAX;            ansmax=INT_MIN;            QueryX(1,n,1);            ans=(ansmin+ansmax)/2;            printf("%d\n",ans);            UpDataX(1,n,1);        }    }    return 0;}
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