读错题+网络流==50分

#include <cstdio>
#include <cstring>
using namespace std;
#define re register int 
#define in inline 
#define inf 99999999
#define maxn 100005
#define maxm 20000006
#define mod 100000

int n,m,s,t,tt;
int ans=0;

struct node{
	int to,next,ti;
}bian[maxm];
int head[maxn];
int cnt=1;
int mx[maxn];
int mi[maxn];

int dui[maxn];
int dis[maxn];
int front,rear;
int ins[maxn];

in int min(int a,int b)
{
	if(a<b) return a;
	return b;
}
in int max(int a,int b)
{
	if(a>b) return a;
	return b;
}
in void add(int u,int v,int ti)
{
	cnt++;
	bian[cnt].to=v;
	bian[cnt].ti=ti;
	bian[cnt].next=head[u];
	head[u]=cnt;
}
in int read()
{
	int ans=0;
	char ch=getchar();
	for(;ch<'0'||ch>'9';ch=getchar()) ;
	for(;ch>='0'&&ch<='9';ch=getchar()) ans=ans*10+ch-'0';
	return ans;
}
void build()
{
	re i,j;
	for(i=1;i<=n;i++){
		for(j=i+1;j<=n;j++) {
			if(mx[i]<=mx[j]&&mi[i]<=mi[j]) {
				add(i,j,-1);
			}
		}
	}
	for(i=1;i<=n;i++) add(s,i,-1),add(i,tt,0);
	add(tt,t,0);
}
in bool spfa()
{
	re i;
	int u,v;
	for(i=1;i<=n+3;i++) dis[i]=inf;
	dis[s]=0;
	front=1,rear=2;
	dui[1]=s;
	ins[s]=1;
	while(front!=rear){
		u=dui[front];
		ins[u]=0;
		for(i=head[u];i;i=bian[i].next){
			v=bian[i].to;
			if(dis[v]-dis[u]>bian[i].ti){
				dis[v]=dis[u]+bian[i].ti;
				if(!ins[v]) {
					dui[rear]=v;
					ins[v]=1;
					rear++;
					rear%=mod;
				}
			}
		}
		front++;
		front%=mod;
	}
	if(dis[t]!=inf) return 1;
	return 0;
}
int main()
{
	//freopen("sequence.in","r",stdin);
	//freopen("sequence.out","w",stdout);
	n=read(),m=read();
	re i;
	for(i=1;i<=n;i++) mx[i]=read(),mi[i]=mx[i];
	int x,y;
	for(i=1;i<=m;i++){
		x=read(),y=read();
		mx[x]=max(mx[x],y);
		mi[x]=min(mi[x],y);
	}
	s=n+1,t=n+2,tt=n+3;
	build();
	//while(spfa()) adjust();
	//printf("%d\n",-ans);
	spfa();
	printf("%d\n",-dis[t]);
}
/*
3 4
1 2 3
1 2
2 3
2 1
3 4

*/