Laser.cpp

#include<bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 5;

int bit[2][maxn], freqx[maxn], freqy[maxn];

void upd(int id, int tp){
	for(; id < maxn; id+=id&-id) bit[tp][id]++;
}
void nupd(int id, int tp){
	for(; id < maxn; id+=id&-id) bit[tp][id]--;
}

int sum(int id, int tp){
	int rt = 0;
	for(; id>0; id-=id&-id) rt += bit[tp][id];
	return rt;
}

int main(){
	int n, m; cin >> n >> m;
	int q; cin >> q;
	while(q--){
		char tp; cin >> tp;
		int x, y; cin >> x >> y;
		if(tp=='A'){
			if(!freqx[x]) upd(x, 0);
			if(!freqy[y]) upd(y, 1);
			freqx[x]++, freqy[y]++;
		}
		else if(tp=='R'){
			freqx[x]--, freqy[y]--;	
			if(!freqx[x]) nupd(x, 0);
			if(!freqy[y]) nupd(y, 1);
		}
		else{
			int x2, y2; cin >> x2 >> y2;
			if(x2<x) swap(x, x2);
			if(y2<y) swap(y, y2);
			if(sum(y2, 1)-sum(y-1, 1) == y2-y+1 || sum(x2, 0)-sum(x-1, 0) == x2-x+1) cout << "S\n";
			else cout << "N\n";
		}
	}
}