HDU 5454 Excited Database (2015年瀋陽賽區網路賽E題)
阿新 • • 發佈:2019-01-04
2.解題思路:本題利用線段樹解決,根據題意,我們需要建立兩棵線段樹,分別維護主對角線,副對角線。每個線段樹的結點需要維護sum,sumL,sumR,其中,sum表示當前區間元素的和,sumL表示[L,R]這段區間中三角形和(第L層從1開始算)的值,sumR類似於sumL。查詢時候把矩形看做一個平行四邊形加上上下兩個三角形來分3次查詢。這樣,本題即可在O(logN)時間內查詢完畢。
3.程式碼:
#include<iostream> #include<algorithm> #include<cassert> #include<string> #include<sstream> #include<set> #include<bitset> #include<vector> #include<stack> #include<map> #include<queue> #include<deque> #include<cstdlib> #include<cstdio> #include<cstring> #include<cmath> #include<ctime> #include<cctype> #include<complex> #include<functional> #pragma comment(linker, "/STACK:1024000000,1024000000") using namespace std; #define rep(i,n) for(int i=0;i<(n);i++) #define me(s) memset(s,0,sizeof(s)) #define pb push_back #define lid (id<<1) #define rid (id<<1|1) typedef long long ll; typedef unsigned long long ull; typedef pair<int,int> P; const int N=400000+5; struct Node { int l,r; ll sum; ll sumL,sumR; ll lazy; int length(){return r-l+1;} int mid(){return l+(r-l)/2;} void maintain(ll a) { lazy+=a; sum+=a*length(); ll add=a*(length()+1)*length()/2; sumL+=add; sumR+=add; } }; Node A[N<<2],D[N<<2]; void pushup(Node*t,int id) { t[id].sum=t[lid].sum+t[rid].sum; t[id].sumL=t[lid].sumL+t[rid].sumL+t[rid].sum*t[lid].length(); //大三角形=左兒子三角形+右兒子三角形+平行四邊形 t[id].sumR=t[lid].sumR+t[rid].sumR+t[lid].sum*t[rid].length(); } void pushdown(Node*t,int id) { if(t[id].lazy) { t[lid].maintain(t[id].lazy); t[rid].maintain(t[id].lazy); t[id].lazy=0; } } void build(Node*t,int id,int L,int R) { t[id].l=L,t[id].r=R; t[id].sum=t[id].sumL=t[id].sumR=t[id].lazy=0; if(L==R)return; int mid=t[id].mid(); build(t,lid,L,mid); build(t,rid,mid+1,R); pushup(t,id); } void update(Node*t,int id,int L,int R,int v) { int l=t[id].l,r=t[id].r; if(L<=l&&r<=R) { t[id].maintain(v); return; } pushdown(t,id); int mid=t[id].mid(); if(L<=mid)update(t,lid,L,R,v); if(R>mid)update(t,rid,L,R,v); pushup(t,id); } ll query(Node*t,int id,int L,int R) { int l=t[id].l,r=t[id].r; if(L<=l&&r<=R) return t[id].sum; pushdown(t,id); int mid=t[id].mid(); ll res=0; if(L<=mid)res+=query(t,lid,L,R); if(R>mid)res+=query(t,rid,L,R); pushup(t,id); return res; } ll queryLeft(Node*t,int id,int L,int R) { int l=t[id].l,r=t[id].r; if(L<=l&&r<=R) return t[id].sumL+t[id].sum*(l-L); //小三角形+平行四邊形(平行四邊形可能不存在) pushdown(t,id); int mid=t[id].mid(); ll res=0; if(L<=mid)res+=queryLeft(t,lid,L,R); if(R>mid)res+=queryLeft(t,rid,L,R); pushup(t,id); return res; } ll queryRight(Node*t,int id,int L,int R) { int l=t[id].l,r=t[id].r; if(L<=l&&r<=R) return t[id].sumR+t[id].sum*(R-r); pushdown(t,id); int mid=t[id].mid(); ll res=0; if(L<=mid)res+=queryRight(t,lid,L,R); if(R>mid)res+=queryRight(t,rid,L,R); pushup(t,id); return res; } int n,q; int main() { int T; int rnd=0; scanf("%d",&T); while(T--) { printf("Case #%d:\n",++rnd); scanf("%d%d",&n,&q); build(A,1,2,2*n); build(D,1,1,2*n-1); int cmd; while(q--) { scanf("%d",&cmd); int L,R; int x1,x2,y1,y2; if(cmd==1) { scanf("%d%d",&L,&R); update(A,1,L,R,1); } if(cmd==2) { scanf("%d%d",&L,&R); update(D,1,L+n,R+n,1); } if(cmd==3) { scanf("%d%d%d%d",&x1,&x2,&y1,&y2); ll ans=0; ll num=min(x2-x1,y2-y1)+1; int l=x2+y1,r=x1+y2; if(l>r)swap(l,r); ans+=query(A,1,l,r)*num; ans+=queryLeft(A,1,x1+y1,l-1); ans+=queryRight(A,1,r+1,x2+y2); l=x1-y1+n,r=x2-y2+n; if(l>r)swap(l,r); ans+=query(D,1,l,r)*num; ans+=queryLeft(D,1,x1-y2+n,l-1); ans+=queryRight(D,1,r+1,x2-y1+n); printf("%lld\n",ans); } } } }