Problem p02727 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstring>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <time.h>
#include <tuple>
#include <vector>
using namespace std;
const double PI = 3.14159265358979323846;
const long long int MOD = 1000000000 + 7;

struct UnionFind {
  vector<int> parent;

  UnionFind(int N) : parent(N) {
    for (int i = 0; i < N; i++) {
      parent[i] = -1;
    }
  }

  int root(int i) {
    if (parent[i] < 0) {
      return i;
    }
    return (parent[i] = root(parent[i]));
  }

  bool unite(int from, int to) {
    int rx = root(from);
    int ry = root(to);
    if (rx != ry) {
      parent[ry] += parent[rx];
      parent[rx] = ry;

      return true;
    } else {
      return false;
    }
  }

  bool same(int x, int y) { return root(x) == root(y); }

  int treeSize(int x) { return -parent[root(x)]; }
};

long long int modpow(long long int base, long long int pow, long long int mod) {
  if (pow == 1) {
    return base;
  } else if (pow == 0) {
    return 1;
  }

  if (pow % 2 == 0) {
    auto temp = modpow(base, pow / 2, mod);
    return (temp * temp) % mod;
  } else {
    return (base * modpow(base, pow - 1, mod)) % mod;
  }
}

long long int moddiv(long long int X, long long int Y, long long int mod) {
  auto fermatDiv = modpow(Y, mod - 2, mod);

  return (X * fermatDiv) % mod;
}

long long modCombination(long long left, long long right, long long int mod) {
  long long answer = 1;
  if (left > right) {
    for (long long i = 0; i < right; i++) {
      answer = (answer * (left - i)) % mod;
      answer = moddiv(answer, (i + 1), mod);
    }
  }
  return answer;
}

bool IsPrime(long long N) {
  if (N == 1) {
    return false;
  }
  for (long long i = 2; i * i <= N; i++) {
    if (N % i == 0) {
      return false;
    }
  }

  return true;
}

vector<pair<long long, long long>> prime_factorize(long long N) {
  vector<pair<long long, long long>> res;
  for (long long a = 2; a * a <= N; ++a) {
    if (N % a != 0)
      continue;
    long long ex = 0; // 指数

    // 割れる限り割り続ける
    while (N % a == 0) {
      ++ex;
      N /= a;
    }

    // その結果を push
    res.push_back({a, ex});
  }

  // 最後に残った数について
  if (N != 1)
    res.push_back({N, 1});
  return res;
}

long long euclid(long long a, long long b) {
  if (a > b) {
    long long temp = b;
    b = a;
    a = temp;
  }
  if (b % a == 0) {
    return a;
  } else {
    return euclid(a, b - a);
  }
}

long long gcd(long long a, long long b) {
  if (b > a) {
    long long temp = b;
    b = a;
    a = temp;
  }
  // cout << "a:" << a << "b:" << b << endl;
  long long c = a % b;
  if (c == 0) {
    return b;
  } else {
    return gcd(b, c);
  }
}

int main() {
  int X, Y, A, B, C;
  cin >> X >> Y >> A >> B >> C;
  vector<int> p(A), q(B), r(C);
  for (int i = 0; i < A; i++) {
    int temp;
    cin >> temp;
    p[i] = temp;
  }

  for (int i = 0; i < B; i++) {
    int temp;
    cin >> temp;
    q[i] = temp;
  }

  for (int i = 0; i < C; i++) {
    int temp;
    cin >> temp;
    r[i] = temp;
  }

  sort(p.begin(), p.end(), greater<int>());
  sort(q.begin(), q.end(), greater<int>());
  sort(r.begin(), r.end(), greater<int>());

  vector<int> eats(X + Y);
  for (int i = 0; i < X; i++) {
    eats[i] = p[i];
  }

  for (int i = 0; i < Y; i++) {
    eats[X + i] = q[i];
  }

  sort(eats.begin(), eats.end());

  for (int i = 0; i < C; i++) {
    if (eats[i] <= r[i]) {
      eats[i] = r[i];
    } else {
      break;
    }
  }

  long long total = 0;
  for (auto e : eats) {
    total += e;
  }

  cout << total << endl;
  return 0;
}

Fixed submission:
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstring>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <time.h>
#include <tuple>
#include <vector>
using namespace std;
const double PI = 3.14159265358979323846;
const long long int MOD = 1000000000 + 7;

struct UnionFind {
  vector<int> parent;

  UnionFind(int N) : parent(N) {
    for (int i = 0; i < N; i++) {
      parent[i] = -1;
    }
  }

  int root(int i) {
    if (parent[i] < 0) {
      return i;
    }
    return (parent[i] = root(parent[i]));
  }

  bool unite(int from, int to) {
    int rx = root(from);
    int ry = root(to);
    if (rx != ry) {
      parent[ry] += parent[rx];
      parent[rx] = ry;

      return true;
    } else {
      return false;
    }
  }

  bool same(int x, int y) { return root(x) == root(y); }

  int treeSize(int x) { return -parent[root(x)]; }
};

long long int modpow(long long int base, long long int pow, long long int mod) {
  if (pow == 1) {
    return base;
  } else if (pow == 0) {
    return 1;
  }

  if (pow % 2 == 0) {
    auto temp = modpow(base, pow / 2, mod);
    return (temp * temp) % mod;
  } else {
    return (base * modpow(base, pow - 1, mod)) % mod;
  }
}

long long int moddiv(long long int X, long long int Y, long long int mod) {
  auto fermatDiv = modpow(Y, mod - 2, mod);

  return (X * fermatDiv) % mod;
}

long long modCombination(long long left, long long right, long long int mod) {
  long long answer = 1;
  if (left > right) {
    for (long long i = 0; i < right; i++) {
      answer = (answer * (left - i)) % mod;
      answer = moddiv(answer, (i + 1), mod);
    }
  }
  return answer;
}

bool IsPrime(long long N) {
  if (N == 1) {
    return false;
  }
  for (long long i = 2; i * i <= N; i++) {
    if (N % i == 0) {
      return false;
    }
  }

  return true;
}

vector<pair<long long, long long>> prime_factorize(long long N) {
  vector<pair<long long, long long>> res;
  for (long long a = 2; a * a <= N; ++a) {
    if (N % a != 0)
      continue;
    long long ex = 0; // 指数

    // 割れる限り割り続ける
    while (N % a == 0) {
      ++ex;
      N /= a;
    }

    // その結果を push
    res.push_back({a, ex});
  }

  // 最後に残った数について
  if (N != 1)
    res.push_back({N, 1});
  return res;
}

long long euclid(long long a, long long b) {
  if (a > b) {
    long long temp = b;
    b = a;
    a = temp;
  }
  if (b % a == 0) {
    return a;
  } else {
    return euclid(a, b - a);
  }
}

long long gcd(long long a, long long b) {
  if (b > a) {
    long long temp = b;
    b = a;
    a = temp;
  }
  // cout << "a:" << a << "b:" << b << endl;
  long long c = a % b;
  if (c == 0) {
    return b;
  } else {
    return gcd(b, c);
  }
}

int main() {
  int X, Y, A, B, C;
  cin >> X >> Y >> A >> B >> C;
  vector<int> p(A), q(B), r(C);
  for (int i = 0; i < A; i++) {
    int temp;
    cin >> temp;
    p[i] = temp;
  }

  for (int i = 0; i < B; i++) {
    int temp;
    cin >> temp;
    q[i] = temp;
  }

  for (int i = 0; i < C; i++) {
    int temp;
    cin >> temp;
    r[i] = temp;
  }

  sort(p.begin(), p.end(), greater<int>());
  sort(q.begin(), q.end(), greater<int>());
  sort(r.begin(), r.end(), greater<int>());

  vector<int> eats(X + Y);
  for (int i = 0; i < X; i++) {
    eats[i] = p[i];
  }

  for (int i = 0; i < Y; i++) {
    eats[X + i] = q[i];
  }

  sort(eats.begin(), eats.end());

  for (int i = 0; i < min(C, X + Y); i++) {
    if (eats[i] <= r[i]) {
      eats[i] = r[i];
    } else {
      break;
    }
  }

  long long total = 0;
  for (auto e : eats) {
    total += e;
  }

  cout << total << endl;
  return 0;
}