Problem p03765 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <bitset>
#include <cassert>
#include <ciso646>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ul;
typedef unsigned int ui;
typedef long double ld;
const int inf = 1e9 + 7;
const ll INF = 1LL << 60;
const ll mod = 1e9 + 7;
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define Rep(i, sta, n) for (int i = sta; i < n; i++)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define per1(i, n) for (int i = n; i >= 1; i--)
#define Rep1(i, sta, n) for (int i = sta; i <= n; i++)
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<int, int> P;
typedef pair<ld, ld> LDP;
typedef pair<ll, ll> LP;
#define fr first
#define sc second
#define all(c) c.begin(), c.end()
#define pb push_back
#define debug(x) cout << #x << " = " << (x) << endl;
using Graph = vector<vector<int>>;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
// #define int long long

// 連続部分列は累積的構造で考えるとよし！！！！！！！！！！！！

void solve() {
  string s, t;
  cin >> s >> t;
  int n = s.size(), m = t.size();
  vector<int> S(n + 1, 0), T(m + 1, 0);
  rep(i, n) {
    if (s[i] == 'A') {
      S[i + 1] = S[i] + 2;
    } else {
      S[i + 1] = S[i] + 1;
    }
  }
  rep(i, n) {
    if (t[i] == 'A') {
      T[i + 1] = T[i] + 2;
    } else {
      T[i + 1] = T[i] + 1;
    }
  }
  int q;
  cin >> q;
  while (q--) {
    int a, b, c, d;
    cin >> a >> b >> c >> d;
    --a;
    --c;
    if ((S[b] - S[a]) % 3 == (T[d] - T[c]) % 3) {
      cout << "YES" << endl;
    } else {
      cout << "NO" << endl;
    }
  }
}

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  // cout << fixed << setprecision(10);
  // init();
  solve();
  // cout << "finish" << endl;
  return 0;
}

Fixed submission:
#include <algorithm>
#include <bitset>
#include <cassert>
#include <ciso646>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ul;
typedef unsigned int ui;
typedef long double ld;
const int inf = 1e9 + 7;
const ll INF = 1LL << 60;
const ll mod = 1e9 + 7;
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define Rep(i, sta, n) for (int i = sta; i < n; i++)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define per1(i, n) for (int i = n; i >= 1; i--)
#define Rep1(i, sta, n) for (int i = sta; i <= n; i++)
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<int, int> P;
typedef pair<ld, ld> LDP;
typedef pair<ll, ll> LP;
#define fr first
#define sc second
#define all(c) c.begin(), c.end()
#define pb push_back
#define debug(x) cout << #x << " = " << (x) << endl;
using Graph = vector<vector<int>>;
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
// #define int long long

// 連続部分列は累積的構造で考えるとよし！！！！！！！！！！！！

void solve() {
  string s, t;
  cin >> s >> t;
  int n = s.size(), m = t.size();
  vector<int> S(n + 1, 0), T(m + 1, 0);
  rep(i, n) {
    if (s[i] == 'A') {
      S[i + 1] = S[i] + 2;
    } else {
      S[i + 1] = S[i] + 1;
    }
  }
  rep(i, m) {
    if (t[i] == 'A') {
      T[i + 1] = T[i] + 2;
    } else {
      T[i + 1] = T[i] + 1;
    }
  }
  int q;
  cin >> q;
  while (q--) {
    int a, b, c, d;
    cin >> a >> b >> c >> d;
    --a;
    --c;
    if ((S[b] - S[a]) % 3 == (T[d] - T[c]) % 3) {
      cout << "YES" << endl;
    } else {
      cout << "NO" << endl;
    }
  }
}

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  // cout << fixed << setprecision(10);
  // init();
  solve();
  // cout << "finish" << endl;
  return 0;
}