上次脑抽帖子

但为什么我把点权取反跑最短路还是WA4个点。（虽然DP已经过了）

Code:

#include<bits/stdc++.h>
#define int  long long
using namespace std;
int h,w,p[200005],val[200005],dis[200005],vis[200005];
int id(int x,int y){
	return (x-1)*w+y;
}
pair<int,int>pir(int idx){
	if(idx%w==0){
		return {idx/w,w};
	}else{
		return {idx/w+1,idx%w};
	}
}
int dx[2]={1,0},dy[2]={0,1};
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>>q;
bool check(int mid){
	while(!q.empty())q.pop();
	memset(dis,0,sizeof dis);
	memset(vis,0,sizeof vis);
	if(mid+val[1]>0)return false;
	q.push({mid+val[1],1});
	dis[1]=mid+val[1];
	while(!q.empty()){
		auto u=q.top();
		q.pop();
		pair<int,int>pos=pir(u.second);
		int x=pos.first,y=pos.second;
		if(x==h&&y==w)return true;
		if(vis[id(x,y)])continue;
		vis[id(x,y)]=1;
		for(int i=0;i<2;i++){
			int nx=x+dx[i],ny=y+dy[i];
			if(nx>h||ny>w)continue;
			if(dis[id(x,y)]+val[id(nx,ny)]<=dis[id(nx,ny)]&&vis[id(nx,ny)]==0){
				dis[id(nx,ny)]=dis[id(x,y)]+val[id(nx,ny)];
				q.push({dis[id(nx,ny)],id(nx,ny)});
			}
		}
	}
	return false;
}
signed main(){
	cin>>h>>w;
	for(int i=1;i<=h;i++){
		for(int j=1;j<=w;j++){
			cin>>val[id(i,j)];
		}
	}
	for(int i=1;i<h+w;i++)cin>>p[i];
	for(int i=1;i<=h;i++){
		for(int j=1;j<=w;j++){
			val[id(i,j)]-=p[i+j-1];
			val[id(i,j)]=-val[id(i,j)];
		}
	}
	int l=-1e18,r=0,ans=0;
	while(l<=r){
		int mid=(l+r)/2;
		if(check(mid))l=mid+1,ans=mid;
		else r=mid-1;
	}
	cout<<-ans;
}