HDU1892二维树状数组求子段和

HDU1892二维树状数组求子段和

http://acm.hdu.edu.cn/showproblem.php?pid=1892
二维树状数组求子段和

#include  < iostream >

using   namespace  std;

const   int  MAX = 1002 ;
int  a[MAX][MAX],c[MAX][MAX];

int  lowbit( int  i)
{
    return i&(-i);
}

int  max( int  i, int  j)
{
    return i>j? i:j;
}

int  min( int  i, int  j)
{
    return i<j? i:j;
}

void  modify( int  x, int  y, int  num)
{
    int i,j;
    for(i=x;i<MAX;i+=lowbit(i))
        for(j=y;j<MAX;j+=lowbit(j))
            c[i][j]+=num;
}

int  sum( int  x, int  y)
{
    int s=0,i,j;
    for(i=x;i>0;i-=lowbit(i))
        for(j=y;j>0;j-=lowbit(j))
            s+=c[i][j];
    return s;
}

void  init()
{
    int i,j;
    for(i=1;i<MAX;i++)
        for(j=1;j<MAX;j++)
        {
            a[i][j]=1;
            c[i][j]=lowbit(i)*lowbit(j);
        }
}

int  main()
{
    
    int i,n,t,j,s,x1,x2,y1,y2,maxx,maxy,minx,miny,temp,x,y,num;
        char ch;
        scanf("%d",&t);
        for(i=1;i<=t;i++)
        {
            init();
            scanf("%d",&n);
            printf("Case %d:\n",i);
            while(n--)
            {
                getchar();
                scanf("%c ",&ch);
                if(ch=='S')
                {
                    scanf("%d %d %d %d",&x1,&y1,&x2,&y2);
                    x1++;y1++;x2++;y2++;
                    maxx=max(x1,x2);
                    maxy=max(y1,y2);
                    minx=min(x1,x2);
                    miny=min(y1,y2);
                    
                    temp=sum(maxx,miny-1)+sum(minx-1,maxy)-sum(minx-1,miny-1);
                    s=sum(maxx,maxy)-temp;
                    printf("%d\n",s);
                    continue;
                }
                if(ch=='A')
                {
                    scanf("%d %d %d",&x,&y,&num);
                    x++;y++;
                    a[x][y]+=num;
                    modify(x,y,num);
                    continue;
                }
                if(ch=='D')
                {
                    scanf("%d %d %d",&x,&y,&num);
                    x++;y++;
                    if(num>a[x][y])
                        num=a[x][y];
                    a[x][y]-=num;
                    modify(x,y,-num);
                    continue;
                }
                if(ch=='M')
                {
                    scanf("%d %d %d %d %d",&x1,&y1,&x2,&y2,&num);
                    x1++;y1++;x2++;y2++;
                    if(num>a[x1][y1])
                        num=a[x1][y1];
                    a[x1][y1]-=num;
                    a[x2][y2]+=num;
                    modify(x1,y1,-num);
                    modify(x2,y2,num);
                    continue;
                }
            }
        }
    return 0;
}