34分 求帮助

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<queue>
#include<string>
#include<cstring>
const int inf=2147483647;
const int maxn=2500050;
using namespace std;

int m,n,xvis[maxn],vis[maxn],head[maxn],t,now=1;
long long dis[maxn];
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>>q;
struct edge {
	int next,v,w;
} e[maxn];
void addedge(int u,int v,int w) {
	e[++t].v=v;
	e[t].w=w;
	e[t].next=head[u];
	head[u]=t;
}
//void my_printf() {
//	q.push(make_pair(0,1));
//	while(!q.empty()) {
//		int x=q.top().second();
//		q.pop();
//		if(vis[x])continue;
//		vis[x]=1;
//		for(int i=head[x]; i; i=e[i].next) {
//			int w=e[i].w;
//			cout<<i<<"->"<<e[i].v<<" "<<e[i].w<<endl;
//		}
//	}
//}
void _DIJ() {
	q.push(make_pair(0,1));
	dis[1]=0;
	while(!q.empty()) {
		int x=q.top().second;
		q.pop();
		if(vis[x]||xvis[x])continue;
		vis[x]=1;
		for(int i=head[x]; i; i=e[i].next) {
			int w=e[i].w;
			int y=e[i].v;
			if (y==0)continue;
			if(dis[y]>dis[x]+w) {
				dis[y]=dis[x]+w;
				if(!vis[y]&&!xvis[y])
				q.push(make_pair(dis[y],y));
			}
		}
	}
}
int main() {
	scanf("%d%d",&n,&m);
	for(int i=1; i<=n; i++) {
		for(int j=1; j<=m; j++) {
		//	printf("inOK\n");
			char a;
			cin>>a;
			if(a=='E') {
				if(now+1<=m*i)addedge(now,now+1,0);
				if(now+m<=m*n)addedge(now,now+m,1);
				if(now-1>=4*i-4)addedge(now,now-1,2);
				if(now-m>=1)addedge(now,now-m,3);
				now++;
			} else if(a=='S') {
				if(now+1<=m*i)addedge(now,now+1,3);
				if(now+m<=m*n)addedge(now,now+m,0);
				if(now-1>=4*i-4)addedge(now,now-1,1);
				if(now-m>=1)addedge(now,now-m,2);
				now++;
			} else if(a=='W') {
				if(now+1<=m*i)addedge(now,now+1,2);
				if(now+m<=m*n)addedge(now,now+m,3);
				if(now-1>=4*i-4)addedge(now,now-1,0);
				if(now-m>=1)addedge(now,now-m,1);
				now++;
			} else if(a=='N') {
				if(now+1<=m*i)addedge(now,now+1,1);
				if(now+m<=m*n)addedge(now,now+m,2);
				if(now-1>=4*i-4)addedge(now,now-1,3);
				if(now-m>=1)addedge(now,now-m,0);
				now++;
			}else if(a=='X'&&m==1&&n==1){
				printf("-1\n");return 0;
			} 			
			else {
				xvis[now]=1;
				now++;
			}
		}
	}
	for(int i=1; i<=m*n; i++)
		dis[i]=inf;
	//my_printf();
	_DIJ();
	if(dis[m*n]==inf)printf("-1\n");
	else printf("%lld\n",dis[m*n]);
	return 0;
}