hdu-1892 See you~---二维树状数组运用

题目链接：

http://acm.hdu.edu.cn/showproblem.php?pid=1892

题目大意：

题目大意：有很多方格，每个方格对应的坐标为（I,J),刚开始时每个格子里有1本书，然后让你统计一片区域有多少本书，还可以增加书和减少，移动书。

解题思路：

直接二维数组数组模拟

注意：

每个下标+1，从(1, 1)开始

求区域和的时候给出的x1 y1 和x2 y2不是标准的正对角线，需要转化

 #include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<string>
#include<cmath>
#include<set>
#include<queue>
#include<map>
#include<stack>
#include<vector>
#include<list>
#include<deque>
#include<sstream>
#include<cctype>
#define REP(i, n) for(int i = 0; i < (n); i++)
#define FOR(i, s, t) for(int i = (s); i < (t); i++)
#define MEM(a, x) memset(a, x, sizeof(a));
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int maxn = 1010;
const double eps = 1e-10;
const int INF = 1 << 30;
const int dir[4][2] = {1,0,0,1,0,-1,-1,0};
const double pi = 3.1415926535898;
int T, n, m, cases;
int tree[maxn][maxn], a[maxn][maxn];
int lowbit(int x)
{
    return x&(-x);
}
int sum(int x, int y)
{
    int ans = 0;
    for(int i = x; i > 0; i -= lowbit(i))
        for(int j = y; j > 0; j -= lowbit(j))
        ans += tree[i][j];
    return ans;
}
void add(int x, int y, int d)
{
    for(int i = x; i < maxn; i += lowbit(i))
    {
        for(int j = y; j < maxn; j += lowbit(j))
        {
            tree[i][j] += d;
        }
    }
}
int main()
{
    scanf("%d", &T);
    char s[3];
    int x, y, x1, y1, x2, y2, d;
    while(T--)
    {
        scanf("%d", &n);
        MEM(tree, 0);
        for(int i = 1; i < maxn; i++)
        {
            for(int j = 1; j < maxn; j++)
            {
                add(i, j, 1);
                a[i][j] = 1;
            }
        }
        printf("Case %d:
", ++cases);
        while(n--)
        {
            scanf("%s", s);
            if(s[0] == 'S')
            {
                scanf("%d%d%d%d", &x1, &y1, &x2, &y2);
                ///不是标准的x1<x2, y1<y2，要对其进行转化
                int a, b, c, d;
                a = min(x1, x2);a++;
                b = min(y1, y2);b++;
                c = max(x1, x2);c++;
                d = max(y1, y2);d++;
                printf("%d
", sum(c, d) + sum(a - 1, b - 1) - sum(a - 1, d) - sum(c, b - 1));
            }
            else if(s[0] == 'A')
            {
                scanf("%d%d%d", &x, &y, &d);
                x++, y++;
                add(x, y, d);
                a[x][y] += d;
            }
            else if(s[0] == 'D')
            {
                scanf("%d%d%d", &x, &y, &d);
                x++, y++;
                if(d > a[x][y])d = a[x][y];
                add(x, y, -d);
                a[x][y] -= d;
            }
            else
            {
                scanf("%d%d%d%d%d", &x1, &y1, &x2, &y2, &d);
                x1++, y1++, x2++, y2++;
                if(d > a[x1][y1])d = a[x1][y1];
                add(x1, y1, -d);
                add(x2, y2, d);
                a[x1][y1] -= d;
                a[x2][y2] += d;
            }
        }
    }
    return 0;
}