hdu 4819 二维线段树模板

Posted 2020-10-02 Pealicx

/*
HDU 4819 Mosaic
题意：查询某个矩形内的最大最小值，
      修改矩形内某点的值为该矩形（Mi+MA）/2;
二维线段树模板：
    区间最值，单点更新。
*/
#include<bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
const int MAXN = 1010;
int N, Q;
struct Nodey
{
    int l, r;
    int Max, Min;
};
int locx[MAXN], locy[MAXN];
struct Nodex
{
    int l, r;
    Nodey sty[MAXN * 4];
    void build(int i, int _l, int _r)
    {
        sty[i].l = _l;
        sty[i].r = _r;
        sty[i].Max = -INF;
        sty[i].Min = INF;
        if(_l == _r)
        {
            locy[_l] = i;
            return;
        }
        int mid = (_l + _r) / 2;
        build(i << 1, _l, mid);
        build((i << 1) | 1, mid + 1, _r);
    }
    int queryMin(int i, int _l, int _r)
    {
        if(sty[i].l == _l && sty[i].r == _r)
            return sty[i].Min;
        int mid = (sty[i].l + sty[i].r) / 2;
        if(_r <= mid)
            return queryMin(i << 1, _l, _r);
        else if(_l > mid)
            return queryMin((i << 1) | 1, _l, _r);
        else
            return min(queryMin(i << 1, _l, mid), queryMin((i << 1) | 1, mid + 1, _r));
    }
    int queryMax(int i, int _l, int _r)
    {
        if(sty[i].l == _l && sty[i].r == _r)
            return sty[i].Max;
        int mid = (sty[i].l + sty[i].r) / 2;
        if(_r <= mid)
            return queryMax(i << 1, _l, _r);
        else if(_l > mid)
            return queryMax((i << 1) | 1, _l, _r);
        else
            return max(queryMax(i << 1, _l, mid), queryMax((i << 1) | 1, mid + 1, _r));
    }
} stx[MAXN * 4];
void build(int i, int l, int r)
{
    stx[i].l = l;
    stx[i].r = r;
    stx[i].build(1, 1, N);
    if(l == r)
    {
        locx[l] = i;
        return;
    }
    int mid = (l + r) / 2;
    build(i << 1, l, mid);
    build((i << 1) | 1, mid + 1, r);
}
//单点修改值
void Modify(int x, int y, int val)
{
    int tx = locx[x];
    int ty = locy[y];
    stx[tx].sty[ty].Min = stx[tx].sty[ty].Max = val;
    for(int i = tx; i; i >>= 1)
        for(int j = ty; j; j >>= 1)
        {
            if(i == tx && j == ty)continue;
            if(j == ty)
            {
                stx[i].sty[j].Min = min(stx[i << 1].sty[j].Min, stx[(i << 1) | 1].sty[j].Min);
                stx[i].sty[j].Max = max(stx[i << 1].sty[j].Max, stx[(i << 1) | 1].sty[j].Max);
            }
            else
            {
                stx[i].sty[j].Min = min(stx[i].sty[j << 1].Min, stx[i].sty[(j << 1) | 1].Min);
                stx[i].sty[j].Max = max(stx[i].sty[j << 1].Max, stx[i].sty[(j << 1) | 1].Max);
            }
        }
}

int queryMin(int i, int x1, int x2, int y1, int y2)
{
    if(stx[i].l == x1 && stx[i].r == x2)
        return stx[i].queryMin(1, y1, y2);
    int mid = (stx[i].l + stx[i].r) / 2;
    if(x2 <= mid)
        return queryMin(i << 1, x1, x2, y1, y2);
    else if(x1 > mid)
        return queryMin((i << 1) | 1, x1, x2, y1, y2);
    else
        return min(queryMin(i << 1, x1, mid, y1, y2), queryMin((i << 1) | 1, mid + 1, x2, y1, y2));
}
int queryMax(int i, int x1, int x2, int y1, int y2)
{
    if(stx[i].l == x1 && stx[i].r == x2)
        return stx[i].queryMax(1, y1, y2);
    int mid = (stx[i].l + stx[i].r) / 2;
    if(x2 <= mid)
        return queryMax(i << 1, x1, x2, y1, y2);
    else if(x1 > mid)
        return queryMax((i << 1) | 1, x1, x2, y1, y2);
    else
        return max(queryMax(i << 1, x1, mid, y1, y2), queryMax((i << 1) | 1, mid + 1, x2, y1, y2));
}


int main()
{
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    int T, ic = 0;
    scanf("%d", &T);
    while(T--)
    {
        printf("Case #%d:\n", ++ic);
        scanf("%d", &N);
        build(1, 1, N);
        for(int i = 1; i <= N; i++)
            for(int j = 1; j <= N; j++)
            {
                int a;
                scanf("%d", &a);
                Modify(i, j, a);
            }
        scanf("%d", &Q);
        while(Q--)
        {
            int x, y, L;
            scanf("%d%d%d", &x, &y, &L);
            int x1 = max(x - L / 2, 1);
            int x2 = min(x + L / 2, N);
            int y1 = max(y - L / 2, 1);
            int y2 = min(y + L / 2, N);
            //(x1,y1)左上角，(x2,y2)右下角
            int Max = queryMax(1, x1, x2, y1, y2);
            int Min = queryMin(1, x1, x2, y1, y2);
            int t = (Max + Min) / 2;
            printf("%d\n", t);
            Modify(x, y, t);//单点修改
        }
    }
    return 0;
}