Problem p01418 (C++) — buggy submission, verdict: Memory Limit Exceeded

#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
// #define LOG(...)
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define REP(i, n) for (int i = 0; i < (int)(n); ++i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define RSORT(c) sort((c).rbegin(), (c).rend())
#define CLR(a) memset((a), 0, sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};

struct UnionFind {
  vector<int> v;
  UnionFind(int n) : v(n) {
    for (int i = 0; i < n; i++)
      v[i] = i;
  }
  int find(int x) { return v[x] == x ? x : v[x] = find(v[x]); }
  void unite(int x, int y) { v[find(x)] = find(y); }
};

int main() {
  int night;
  double r, l, p, e, t;
  cin >> night >> l >> r >> p >> e >> t;
  double ans = 0.0;
  queue<pair<pair<double, double>, double>> Q;
  Q.push({{l, r}, 1.0});
  REP(i, night) {
    int cnt = Q.size();
    REP(j, cnt) {
      pair<pair<double, double>, double> q = Q.front();
      Q.pop();
      if (t + e < q.first.first)
        continue;
      if (t - e > q.first.second)
        continue;
      if (t - e < q.first.first && q.first.second < t + e) {
        Q.push(q);
        continue;
      }
      if ((q.first.first + q.first.second) / 2 >= t) {
        Q.push({{(q.first.first + q.first.second) / 2.0, q.first.second},
                q.second * p});
        Q.push({{q.first.first, (q.first.first + q.first.second) / 2.0},
                q.second * (1.0 - p)});
      } else {
        Q.push({{(q.first.first + q.first.second) / 2.0, q.first.second},
                q.second * (1.0 - p)});
        Q.push({{q.first.first, (q.first.first + q.first.second) / 2.0},
                q.second * p});
      }
    }
  }
  while (!Q.empty()) {
    pair<pair<double, double>, double> q = Q.front();
    Q.pop();
    if (abs((q.first.first + q.first.second) / 2 - t) <= e + 1e-10) {
      ans += q.second;
    }
  }
  printf("%.6lf\\n", ans);
}

Error: MLE

Fixed submission:

#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <functional>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
// #define LOG(...)
#define FOR(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define REP(i, n) for (int i = 0; i < (int)(n); ++i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define RSORT(c) sort((c).rbegin(), (c).rend())
#define CLR(a) memset((a), 0, sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};

struct UnionFind {
  vector<int> v;
  UnionFind(int n) : v(n) {
    for (int i = 0; i < n; i++)
      v[i] = i;
  }
  int find(int x) { return v[x] == x ? x : v[x] = find(v[x]); }
  void unite(int x, int y) { v[find(x)] = find(y); }
};

int main() {
  int night;
  double r, l, p, e, t;
  cin >> night >> l >> r >> p >> e >> t;
  double ans = 0.0;
  queue<pair<pair<double, double>, double>> Q;
  Q.push({{l, r}, 1.0});
  REP(i, night) {
    int cnt = Q.size();
    REP(j, cnt) {
      pair<pair<double, double>, double> q = Q.front();
      Q.pop();
      if (t + e < q.first.first)
        continue;
      if (t - e > q.first.second)
        continue;
      if ((q.first.first + q.first.second) / 2 >= t) {
        Q.push({{(q.first.first + q.first.second) / 2.0, q.first.second},
                q.second * (1.0 - p)});
        Q.push({{q.first.first, (q.first.first + q.first.second) / 2.0},
                q.second * p});
      } else {
        Q.push({{(q.first.first + q.first.second) / 2.0, q.first.second},
                q.second * p});
        Q.push({{q.first.first, (q.first.first + q.first.second) / 2.0},
                q.second * (1.0 - p)});
      }
    }
  }
  while (!Q.empty()) {
    pair<pair<double, double>, double> q = Q.front();
    Q.pop();
    if (abs((q.first.first + q.first.second) / 2 - t) <= e + 1e-10) {
      ans += q.second;
    }
  }
  printf("%.6lf\\n", ans);
}