UVa 11992 (线段树 区间修改) Fast Matrix Operations

比较综合的一道题目。

二维的线段树，支持区间的add和set操作，然后询问子矩阵的sum，min，max

写完这道题也是醉醉哒，代码仓库里还有一份代码就是在query的过程中也pushdown向下传递标记。

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

const int maxnode = 1 << 17;
int _sum, _min, _max, op, x1, x2, y1, y2, x, v;

struct IntervalTree
{
    int maxv[maxnode], minv[maxnode], sumv[maxnode], setv[maxnode], addv[maxnode];

    void maintain(int o, int L, int R)
    {
        int lc = o*2, rc = o*2+1;
        if(R > L)
        {
            sumv[o] = sumv[lc] + sumv[rc];
            minv[o] = min(minv[lc], minv[rc]);
            maxv[o] = max(maxv[lc], maxv[rc]);
        }
        if(setv[o] >= 0) { maxv[o] = minv[o] = setv[o]; sumv[o] = (R-L+1)*setv[o]; }
        if(addv[o]) { minv[o] += addv[o]; maxv[o] += addv[o]; sumv[o] += (R-L+1)*addv[o]; }
    }

    void pushdown(int o)
    {
        int lc = o*2, rc = o*2+1;
        if(setv[o] >= 0)
        {
            setv[lc] = setv[rc] = setv[o];
            addv[lc] = addv[rc] = 0;
            setv[o] = -1;
        }
        if(addv[o])
        {
            addv[lc] += addv[o];
            addv[rc] += addv[o];
            addv[o] = 0;
        }
    }

    void update(int o, int L, int R)
    {
        int lc = o*2, rc = o*2+1;
        if(y1 <= L && R <= y2)
        {
            if(op == 1) addv[o] += v;
            else { setv[o] = v; addv[o] = 0; }
        }
        else
        {
            pushdown(o);    //往下传递标记
            int M = (L + R) / 2;
            if(y1 <= M) update(lc, L, M); else maintain(lc, L, M);
            if(y2 > M) update(rc, M+1, R); else maintain(rc, M+1, R);
        }
        maintain(o, L, R);
    }

    void query(int o, int L, int R, int add)
    {
        if(setv[o] >= 0)
        {
            int v = setv[o] + addv[o] + add;
            _sum += v * (min(y2, R) - max(y1, L) + 1);
            _min = min(_min, v);
            _max = max(_max, v);
        }
        else if(y1 <= L && R <= y2)
        {
            _sum += sumv[o] + add*(R-L+1);
            _min = min(_min, minv[o] + add);
            _max = max(_max, maxv[o] + add);
        }
        else
        {
            int M = (L + R) / 2;
            if(y1 <= M) query(o*2, L, M, add + addv[o]);
            if(y2 > M) query(o*2+1, M+1, R, add + addv[o]);
        }
    }
};

const int maxr = 20 + 5;
const int INF = 1000000000;

IntervalTree tree[maxr];

int main()
{
    //freopen("in.txt", "r", stdin);

    int r, c, m;
    while(scanf("%d%d%d", &r, &c, &m) == 3)
    {
        memset(tree, 0, sizeof(tree));
        for(int x = 1; x <= r; x++)
        {
            memset(tree[x].setv, -1, sizeof(tree[x].setv));
            tree[x].setv[1] = 0;
        }

        while(m--)
        {
            scanf("%d%d%d%d%d", &op, &x1, &y1, &x2, &y2);
            if(op < 3)
            {
                scanf("%d", &v);
                for(x = x1; x <= x2; x++) tree[x].update(1, 1, c);
            }
            else
            {
                _sum = 0; _max = -INF; _min = INF;
                for(x = x1; x <= x2; x++) tree[x].query(1, 1, c, 0);
                printf("%d %d %d
", _sum, _min, _max);
            }
        }
    }

    return 0;
}