loj2090 「ZJOI2016」旅行者

分治+最短路，很套路的

#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
using namespace std;
int n, m, ans[100005], px[20005], py[20005], uu, hea[20005], cnt, q, din;
int dis[20005];
bool vis[20005];
struct Edge{
	int too, nxt, val;
}edge[1000005];
struct Ques{
	int xu, yu, xv, yv, id;
}qu[100005], qq[100005];
struct Node{
	int idx, dis;
}nd[5000005];
int f(int x, int y){
	return (x-1)*m+y;
}
void add_edge(int fro, int too, int val){
	edge[++cnt].nxt = hea[fro];
	edge[cnt].too = too;
	edge[cnt].val = val;
	hea[fro] = cnt;
}
bool inn(int x, int nl, int nr, int ml, int mr){
	if(px[x]>=nl && px[x]<=nr && py[x]>=ml && py[x]<=mr)
		return true;
	return false;
}
bool cmp(Node x, Node y){
	return x.dis>y.dis;
}
void dijkstra(int x, int nl, int nr, int ml, int mr){
	for(int i=nl; i<=nr; i++)
		for(int j=ml; j<=mr; j++){
			dis[f(i,j)] = 0x3f3f3f3f;
			vis[f(i,j)] = false;
		}
	dis[x] = 0;
	din = 1;
	nd[1] = (Node){x, 0};
	while(din){
		int o=nd[1].idx;
		pop_heap(nd+1, nd+1+din, cmp);
		din--;
		if(vis[o])	continue;
		vis[o] = true;
		for(int i=hea[o]; i; i=edge[i].nxt){
			int t=edge[i].too;
			if(inn(t, nl, nr, ml, mr) && dis[t]>dis[o]+edge[i].val){
				dis[t] = dis[o] + edge[i].val;
				nd[++din] = (Node){t, dis[t]};
				push_heap(nd+1, nd+1+din, cmp);
			}
		}
	}
}
void solve(int nl, int nr, int ml, int mr, int ql, int qr){
	if(ql>qr)	return ;
	if(nr-nl>mr-ml){
		int mid=(nl+nr)>>1;
		for(int i=ml; i<=mr; i++){
			int p=f(mid, i);
			dijkstra(p, nl, nr, ml, mr);
			for(int j=ql; j<=qr; j++)
				ans[qu[j].id] = min(ans[qu[j].id], dis[f(qu[j].xu, qu[j].yu)]+dis[f(qu[j].xv, qu[j].yv)]);
		}
		int l=ql, r=qr;
		for(int i=ql; i<=qr; i++)
			if(qu[i].xu<mid && qu[i].xv<mid)	qq[l++] = qu[i];
			else if(qu[i].xu>mid && qu[i].xv>mid)	qq[r--] = qu[i];
		for(int i=ql; i<=qr; i++)
			qu[i] = qq[i];
		solve(nl, mid-1, ml, mr, ql, l-1);
		solve(mid+1, nr, ml, mr, r+1, qr);
	}
	else{
		int mid=(ml+mr)>>1;
		for(int i=nl; i<=nr; i++){
			int p=f(i, mid);
			dijkstra(p, nl, nr, ml, mr);
			for(int j=ql; j<=qr; j++)
				ans[qu[j].id] = min(ans[qu[j].id], dis[f(qu[j].xu, qu[j].yu)]+dis[f(qu[j].xv, qu[j].yv)]);
		}
		int l=ql, r=qr;
		for(int i=ql; i<=qr; i++)
			if(qu[i].yu<mid && qu[i].yv<mid)	qq[l++] = qu[i];
			else if(qu[i].yu>mid && qu[i].yv>mid)	qq[r--] = qu[i];
		for(int i=ql; i<=qr; i++)
			qu[i] = qq[i];
		solve(nl, nr, ml, mid-1, ql, l-1);
		solve(nl, nr, mid+1, mr, r+1, qr);
	}
}
int main(){
	memset(ans, 0x3f, sizeof(ans));
	cin>>n>>m;
	for(int i=1; i<=n; i++)
		for(int j=1; j<m; j++){
			scanf("%d", &uu);
			int p=f(i,j), q=f(i,j+1);
			add_edge(p, q, uu);
			add_edge(q, p, uu);
		}
	for(int i=1; i<n; i++)
		for(int j=1; j<=m; j++){
			scanf("%d", &uu);
			int p=f(i,j), q=f(i+1,j);
			add_edge(p, q, uu);
			add_edge(q, p, uu);
		}
	for(int i=1; i<=n; i++)
		for(int j=1; j<=m; j++){
			int p=f(i,j);
			px[p] = i;
			py[p] = j;
		}
	cin>>q;
	for(int i=1; i<=q; i++){
		scanf("%d %d %d %d", &qu[i].xu, &qu[i].yu, &qu[i].xv, &qu[i].yv);
		qu[i].id = i;
	}
	solve(1, n, 1, m, 1, q);
	for(int i=1; i<=q; i++)
		printf("%d
", ans[i]);
	return 0;
}