【問題描述】 Every time it rains on Farmer John's fields, a pond forms over Bessie's favorite clover patch. This means that the clover is covered by water for awhile and takes quite a long time to regrow. Thus, Farmer John has built a set of d
題意:要求設計這樣一個數據結構,支持下列操作 1.add(x,y,a).對二維數組的第x行,第y列加上a. 2.sum(l,b,r,t).求所有滿足l<=x<=r,b<=y<=t,的數組元素的和. 顯然,二維樹狀數組滿足這些要求. poj1741,code: var c:array[0..1025,0..1025] of longin