欢迎投稿#1voidBuild(intrt,intl,intr){ tree[rt].l=l; tree[rt].r=r; if(l==r) { tree[rt].sum=a[l]; return; } intmid=(l+r)>>1; Build(lson,l,mid); Build(rson,mid+1,r); pushup(rt);}#2voidjian(intk,intl,int