1234C - Pipes - CodeForces Solution

#include<bits/stdc++.h>
using namespace std;
int _;
bool solve() {
  int n; cin >> n;
  vector<vector<int>> a(2, vector<int>(n));
  for(auto &p : a) for(int &pp : p) {
    char in; cin >> in;
    pp=(in<='2' ? 0 : 1);
  }
  int dir=1, r=0, c=0;
  while(r>=0 && c>=0 && r<2 && c<n) {
    if(a[r][c]) {
      if(dir==0 || dir==2) dir=1, c++;
      else dir=2-2*r, r^=1;
    } else {
      if(dir==1) c++;
      else return 0;
    }
  }
  return r && c==n;
}
int main() {
  ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
  cin >> _;
  while(_--) cout << (solve() ? "YES\n" : "NO\n");
  return 0;
}