ABC276E RE两个点，求问为何RE

#include <bits/stdc++.h>
#define int long long
using namespace std;

int h, w;
vector<string> s;
struct XY {
	int x, y, c;
} st;
queue<XY> q;
map<pair<int, int>, int> mp;

void bfs() {
	if(s[st.x-1][st.y] == '.') 
		q.push({st.x-1, st.y, 1}), mp[{st.x-1, st.y}] = 1;
	if(s[st.x+1][st.y] == '.') 
		q.push({st.x+1, st.y, 2}), mp[{st.x+1, st.y}] = 2;
	if(s[st.x][st.y-1] == '.') 
		q.push({st.x, st.y-1, 3}), mp[{st.x, st.y-1}] = 3;
	if(s[st.x][st.y+1] == '.') 
		q.push({st.x, st.y+1, 4}), mp[{st.x, st.y+1}] = 4;
	while(q.size()) {
		XY now = q.front();
		q.pop();
		if(now.x-1 > 0 && s[now.x-1][now.y] == '.') {
			if(!mp[{now.x-1, now.y}]) {
				mp[{now.x-1, now.y}] = now.c;
				q.push({now.x-1, now.y, now.c});
			}
			else if(mp[{now.x-1, now.y}] != now.c)
				printf("Yes"), exit(0);
		}
		if(now.x+1 <= h && s[now.x+1][now.y] == '.') {
			if(!mp[{now.x+1, now.y}]) {
				mp[{now.x+1, now.y}] = now.c;
				q.push({now.x+1, now.y, now.c});
			}
			else if(mp[{now.x+1, now.y}] != now.c)
				printf("Yes"), exit(0);
		}
		if(now.y-1 > 0 && s[now.x][now.y-1] == '.') {
			if(!mp[{now.x, now.y-1}]) {
				mp[{now.x, now.y-1}] = now.c;
				q.push({now.x, now.y-1, now.c});
			}
			else if(mp[{now.x, now.y-1}] != now.c)
				printf("Yes"), exit(0);
		}
		if(now.y+1 <= w && s[now.x][now.y+1] == '.') {
			if(!mp[{now.x, now.y+1}]) {
				mp[{now.x, now.y+1}] = now.c;
				q.push({now.x, now.y+1, now.c});
			}
			else if(mp[{now.x, now.y+1}] != now.c)
				printf("Yes"), exit(0);
		}
	}
}

signed main() {
	scanf("%lld%lld", &h, &w), s.push_back(" ");
	for(int i = 1; i <= h; i++) {
		string t;
		cin >> t;
		for(int j = 0; j < t.size(); j++) 
			if(t[j] == 'S') st = {i, j+1, 0};
		t = ' '+t, s.push_back(t);
	}
	bfs(), printf("No");

	return 0;
}