二維樹狀數組 hdu 1892

簡單的一個二維樹狀數組的應用，沒有變形

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

//二維樹狀數組<br />//<br />#include<stdio.h><br />const int size = 1002;</p><p>int C[size][size];<br />int D[size][size];</p><p>int lowbit(int n)<br />{<br /> return n&(-n);<br />}</p><p>void Modify(int x, int y, int delta)<br />{<br /> for(int i = x; i <= 1001; i += lowbit(i))<br />for(int j = y; j <= 1001; j += lowbit(j))<br />{<br />C[i][j] += delta;<br />}<br />}</p><p>int Sum(int i, int j)<br />{<br />//if(i<=0 || j<=0) return 0;</p><p> int result = 0;<br /> for(int x = i; x > 0; x -= lowbit(x))<br /> {<br /> for(int y = j; y > 0; y -= lowbit(y))<br /> {<br /> result += C[x][y];<br /> }<br /> }</p><p> return result;<br />}</p><p>int min(int x,int y)<br />{<br />return x<y?x:y;<br />}</p><p>int max(int x,int y)<br />{<br />return x>y?x:y;<br />}</p><p>int main()<br />{<br />int cas,q,ca;<br />char str;<br />int x1,y1,x2,y2,n1;<br />int xmin,ymin,xmax,ymax;<br />int ans;<br />scanf("%d",&cas);<br />for(ca = 1;ca <=cas;ca++)<br />{<br />printf("Case %d:/n",ca);<br />//初始化<br />for (x1 = 1;x1 <= 1001;x1++)<br />for (y1 = 1;y1 <= 1001;y1++)<br />{<br />D[x1][y1] = 1;<br />C[x1][y1] = lowbit(x1) * lowbit(y1);<br />}<br />scanf("%d",&q);<br />while (q--)<br />{<br />getchar();<br />scanf("%c",&str);<br />if(str == 'S') //sum<br />{<br />scanf("%d %d %d %d",&x1,&y1,&x2,&y2);<br />x1++;y1++;x2++;y2++;<br />xmax = max(x1,x2);<br /> ymax = max(y1,y2);<br />xmin = min(x1,x2);<br /> ymin = min(y1,y2);<br />int temp = Sum(xmax,ymin-1) + Sum(xmin-1,ymax) - Sum(xmin-1,ymin-1);<br />ans = Sum(xmax,ymax) - temp; //這樣可以防止某些越界<br />printf("%d/n",ans);<br />}<br />else if (str == 'A') //add<br />{<br />scanf("%d %d %d",&x1,&y1,&n1);<br />x1++;y1++;<br />Modify(x1,y1,n1);<br />D[x1][y1] += n1;<br />}<br />else if (str == 'D') //delete<br />{<br />scanf("%d %d %d",&x1,&y1,&n1);<br />x1++;y1++;<br />if(D[x1][y1] < n1) n1 = D[x1][y1];<br />Modify(x1,y1,-n1);<br />D[x1][y1] -= n1;<br />}<br />else if (str == 'M') //move<br />{<br />scanf("%d %d %d %d %d",&x1,&y1,&x2,&y2,&n1);<br />x1++;y1++;x2++;y2++;<br />if (n1 > D[x1][y1])<br />n1 = D[x1][y1];<br />D[x1][y1] -= n1;<br />D[x2][y2] += n1;<br />Modify(x1,y1,-n1);<br /> Modify(x2,y2,n1);<br />}<br />}<br />}<br />return 0;<br />}</p><p>/*<br />100<br />3<br />S 1 1 1 1<br />A 1 1 2<br />S 1 1 1 1<br />3<br />S 1 1 1 1<br />A 1 1 2<br />S 1 1 1 2<br />*/