可能我的dinic和大佬们的有巨大不同

#include<bits/stdc++.h>
using namespace std;
const int N=7*1e6;
const int inf=1e9+90;
int n,m,head[N],tot,now[N],p[300][300],dis[N],s,t,ans;
int move[8][2]={{1,2},{1,-2},{-1,2},{-1,-2},{2,1},{2,-1},{-2,1},{-2,-1}};
//now[]为当前弧优化
struct node{
	int next,v,flow;
}ed[N];

inline int qwe(int i,int j){
	return (i-1)*n+j;
}

inline void add(int x,int y,int z){
	ed[++tot].next=head[x];
	ed[tot].v=y;
	ed[tot].flow=z;
	head[x]=tot;
}

inline bool bfs(){
	queue<int>q;
	for(int i=0;i<=t+1;i++) dis[i]=inf;
	q.push(s);
	dis[s]=0;
	now[s]=head[s];
	while(!q.empty()){
		int x=q.front();
		q.pop();
		for(int i=head[x];i!=-1;i=ed[i].next){
			int v=ed[i].v;
			int f=ed[i].flow;
			if(f>0&&dis[v]==inf){
				dis[v]=dis[x]+1;
				now[v]=head[v];
				q.push(v);
				if(v==t) return 1;
			}
		}
	}
	return 0;
}

inline int dfs(int x,int sum){
	if(x==t) return sum;
	int res=0,k=0;
	for(int i=now[x];i!=0&&sum;i=ed[i].next){
		now[x]=i;//当前弧优化 
		int v=ed[i].v,f=ed[i].flow;
		if(f>0&&dis[v]==dis[x]+1){
			k=dfs(v,min(f,sum));
			if(k==0) dis[v]=inf;//剪枝 
			ed[i].flow-=k;
			ed[i^1].flow+=k;
			res+=k;
			sum-=k;
		}
	}
	return res;
}

int main(){
	scanf("%d%d",&n,&m);
	memset(head,-1,sizeof(head));
	s=0;
	t=n*n+2;
	tot=1;
	for(int i=1;i<=m;i++){
		int x,y;
		scanf("%d%d",&x,&y);
		p[x][y]=1;
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			if((i+j)&1){
				if(!p[i][j]){
					add(s,qwe(i,j),1);
					add(qwe(i,j),s,0);
				}
			}
			else if(!p[i][j]){
				add(qwe(i,j),t,1);
				add(t,qwe(i,j),0);
			}
		}
	}
	for(int i=1;i<=n;i++){
		for(int j=1;j<=n;j++){
			if(!(i+j)&1) continue;
			for(int k=0;k<8;k++){
				int x=i+move[k][0];
				int y=j+move[k][1];
				if(x<=0||x>n||y<=0||y>n||p[x][y]==1) continue;
				add(qwe(i,j),qwe(x,y),inf);
				add(qwe(x,y),qwe(i,j),0);
			}
		}
	}
	while(bfs()){
		ans+=dfs(s,inf);
	}
	printf("%d",n*n-m-ans);
	return 0;
}

目前状况37分

求助，谢谢