【二维树状数组】HDU 1892

注意树状数组的初始化，c[i][j] = lowbit(i)*lowbit(j)与add(i,j,1)等价！

因为树状数组的lowbit作用是提取出x的最低位1.

#define N 1100int c[N][N];int g[N][N];int lowbit(int x){    return x&(-x);}void add(int i,int j,int x){    int tmp;    while(i<N){        tmp = j;        while(tmp<N){            c[i][tmp]+=x;            tmp+=lowbit(tmp);        }        i+=lowbit(i);    }}int sum(int i,int j){    int ans=0;    int tmp;    while(i>0){        tmp = j;        while(tmp>0){            ans+=c[i][tmp];            tmp-=lowbit(tmp);        }        i-=lowbit(i);    }    return ans;}int main(){    int t;    scanf("%d",&t);    int ca=1;    while(t--){        int n;        scanf("%d",&n);        int i,j;        for(i=1;i<N;i++){            for(j=1;j<N;j++){                g[i][j] = 1;                c[i][j] = lowbit(i)*lowbit(j);//add(i,j,1);            }        }        printf("Case %d:\n",ca++);        while(n--){ //0<=x1,y1,x2,y2<=1000            char str[3];            scanf("%s",str);            if(str[0] == 'S'){                int x1,y1,x2,y2;                scanf("%d%d%d%d",&x1,&y1,&x2,&y2);                int x,xx,y,yy;                x = min(x1,x2),xx = max(x1,x2);                x++,xx++;                y = min(y1,y2),yy = max(y1,y2);                y++,yy++;                int ans = sum(xx,yy)-sum(xx,y-1)-sum(x-1,yy)+sum(x-1,y-1);                printf("%d\n",ans);            } else if(str[0] == 'A'){                int x,y,a;                scanf("%d%d%d",&x,&y,&a);                x++,y++;                add(x,y,a);                g[x][y]+=a;            } else if(str[0] == 'D'){                int x,y,a;                scanf("%d%d%d",&x,&y,&a);                x++,y++;                if(a>g[x][y])a = g[x][y];                add(x,y,-a);                g[x][y]-=a;            } else if(str[0] == 'M'){                int x1 ,y1, x2, y2, n1;                scanf("%d%d%d%d%d",&x1,&y1,&x2,&y2,&n1);                x1++,y1++;                x2++,y2++;                if(g[x1][y1]<n1){                    n1 = g[x1][y1];                }                add(x1,y1,-n1);                add(x2,y2,n1);                g[x1][y1] -= n1;                g[x2][y2] += n1;            }        }    }    return 0;}