zoj2859 Matrix Searching

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#define REP(i,a,b) for(int i=a;i<=b;i++)
#define MS0(a) memset(a,0,sizeof(a))
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1

using namespace std;

typedef long long ll;
const int maxn=1200;
const int INF=1e9+10;

int n,q;
int val[maxn][maxn];
int x,y,xt,yt;
struct NodeX
{
    int Min[maxn<<2];
    void up(int rt)
    {
        Min[rt]=min(Min[rt<<1],Min[rt<<1|1]);
    }
    void build(int l,int r,int rt)
    {
        if(l==r){
            Min[rt]=INF;
            return;
        }
        int m=(l+r)>>1;
        build(lson);
        build(rson);
        up(rt);
    }
    void update(int p,int c,int l,int r,int rt)
    {
        if(l==r){
            Min[rt]=min(Min[rt],c);
            return;
        }
        int m=(l+r)>>1;
        if(p<=m) update(p,c,lson);
        else update(p,c,rson);
        up(rt);
    }
    int query(int L,int R,int l,int r,int rt)
    {
        if(L<=l&&r<=R) return Min[rt];
        int m=(l+r)>>1;
        int res=INF;
        if(L<=m) res=min(res,query(L,R,lson));
        if(R>m) res=min(res,query(L,R,rson));
        return res;
    }
};NodeX tx[maxn<<2];

void build(int l,int r,int rt)
{
    tx[rt].build(1,n,1);
    if(l==r) return;
    int m=(l+r)>>1;
    build(lson);
    build(rson);
}

void update(int x,int y,int c,int l,int r,int rt)
{
    tx[rt].update(y,c,1,n,1);
    if(l==r) return;
    int m=(l+r)>>1;
    if(x<=m) update(x,y,c,lson);
    else update(x,y,c,rson);
}

int query(int xL,int xR,int yL,int yR,int l,int r,int rt)
{
    if(xL<=l&&r<=xR) return tx[rt].query(yL,yR,1,n,1);
    int m=(l+r)>>1;
    int res=INF;
    if(xL<=m) res=min(res,query(xL,xR,yL,yR,lson));
    if(xR>m) res=min(res,query(xL,xR,yL,yR,rson));
    return res;
}

int main()
{
    freopen("in.txt","r",stdin);
    int T;cin>>T;
    while(T--){
        scanf("%d",&n);
        REP(i,1,n) REP(j,1,n) scanf("%d",&val[i][j]);
        build(1,n,1);
        REP(i,1,n) REP(j,1,n) update(i,j,val[i][j],1,n,1);
        scanf("%d",&q);
        while(q--){
            scanf("%d%d%d%d",&x,&y,&xt,&yt);
            printf("%d\n",query(x,xt,y,yt,1,n,1));
        }
    }
    return 0;
}