[JSOI2009]计数问题 二维树状数组

～～～题面～～～

题解：

二维树状数组的板子题，，，学了这么久第一次写二维树状数组，惭愧啊。

怎么写就不说了，看代码吧。

跟普通的是一样的写法

#include<bits/stdc++.h>
using namespace std;
#define R register int
#define AC 302
#define lowbit(x) (x & (-x))
int n, m, k;
int a[AC][AC], c[AC][AC][AC];

inline int read()
{
    int x = 0;char c = getchar();
    while(c > '9' || c < '0') c = getchar();
    while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
    return x; 
}

inline void add(int x, int y, int w, int h)
{
    for(R i = x; i <= n; i += lowbit(i))
        for(R j = y; j <= m; j += lowbit(j))
            c[i][j][w] += h; 
}

inline int search(int x, int y, int w)
{
    int ans = 0;
    if(! x || !y || x > n || y > m) return 0;
    for(R i = x; i ; i -= lowbit(i))
        for(R j = y; j ; j -= lowbit(j))
            ans += c[i][j][w];
    return ans;
}

void pre()
{
    n = read(), m = read();
    for(R i = 1; i <= n; i++)
        for(R j = 1; j <= m; j++)
        {
            a[i][j] = read();
            add(i, j, a[i][j], 1);//建立树状数组
        }
}

void work()
{
    int opt, x1, x2, x3, x4, x5, tmp;
    k = read();
    for(R i = 1; i <= k; i++)
    {
        opt = read();
        if(opt == 1)
        {
            x1 = read(), x2 = read(), x3 = read();
            if(x3 != a[x1][x2])
            {
                add(x1, x2, a[x1][x2], -1);//消除原有的值
                add(x1, x2, x3, 1);//新增值
                a[x1][x2] = x3;
            }
        }
        else
        {
            x1 = read(), x3 = read(), x2 = read(), x4 = read(), x5 = read();
            tmp = search(x3, x4, x5) - search(x3, x2 - 1, x5) - search(x1 - 1, x4, x5) + search(x1 - 1, x2 - 1, x5);//error,,,-1啊
            printf("%d
", tmp);
        }
    }
}

int main()
{
//    freopen("in.in", "r", stdin);
    pre();
    work();
//    fclose(stdin);
    return 0;
}