Problem p03038 (C++)

Buggy submission (status: Runtime Error):
// #pragma GCC optimize("Ofast")
// #pragma GCC
// target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
// #pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define FAST                                                                   \
  std::ios_base::sync_with_stdio(false);                                       \
  cin.tie(0);                                                                  \
  cout.tie(0);
#define DECIMAL(n)                                                             \
  std::cout << std::fixed;                                                     \
  std::cout << std::setprecision(n);
#define hell 1000000007
#define narak 998244353
#define PI 3.14159265358979323844
#define mp make_pair
#define eb emplace_back
#define pb push_back
#define fi first
#define se second
#define all(v) v.begin(), v.end()
#define endl "\n"
#define sqr(a) (a) * (a)
#define __lcm(m, n) m *(n / __gcd(m, n))
#define inputarr(a, n)                                                         \
  for (int xxx = 0; xxx < n; ++xxx)                                            \
  cin >> (a)[xxx]
#define sz(a) (int)a.size()
#define sl(a) (int)a.length()
#define display(x)                                                             \
  for (auto &a : x)                                                            \
    cout << a << " ";                                                          \
  cout << endl
#define debug cerr << "bhau" << endl
#define between(n, a, b) (a <= n && n <= b)
#define elasped_time 1.0 * clock() / CLOCKS_PER_SEC

#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1> void __f(const char *name, Arg1 &&arg1) {
  std::cerr << name << " : " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char *names, Arg1 &&arg1, Args &&...args) {
  const char *comma = strchr(names + 1, ',');
  std::cerr.write(names, comma - names) << " : " << arg1 << " | ";
  __f(comma + 1, args...);
}

template <typename T, typename U> static inline void amin(T &x, U y) {
  if (y < x)
    x = y;
}

template <typename T, typename U> static inline void amax(T &x, U y) {
  if (x < y)
    x = y;
}

template <typename T, typename U>
std::ostream &operator<<(std::ostream &out, std::pair<T, U> a) {
  out << a.fi << " " << a.se;
  return out;
}

template <typename T, typename U>
std::istream &operator>>(std::istream &in, std::pair<T, U> &a) {
  in >> a.fi >> a.se;
  return in;
}

inline long long toint(const std::string &s) {
  std::stringstream ss;
  ss << s;
  long long x;
  ss >> x;
  return x;
}
inline std::string tostring(long long number) {
  std::stringstream ss;
  ss << number;
  return ss.str();
}
inline std::string tobin(long long x) { return std::bitset<63>(x).to_string(); }

std::mt19937_64
    rng(std::chrono::steady_clock::now().time_since_epoch().count());

#define ll long long
#define pii std::pair<int, int>
#define vi vector<int>
#define vvi vector<vi>
#define vii vector<pii>
#define point complex<ll>
#define ordered_set                                                            \
  tree<int, null_type, less<int>, rb_tree_tag,                                 \
       tree_order_statistics_node_update>

/*----------------------Graph Moves----------------*/
// const int fx[]={+1,-1,+0,+0};
// const int fy[]={+0,+0,+1,-1};
// const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
// const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
// const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
// const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

// primes for hashing 937,991,1013,1409,1741

using namespace std;
using namespace __gnu_pbds;
#define int long long
void meowmeow321() {
  int n, m;
  cin >> n >> m;
  int a[n];
  inputarr(a, n);
  pii bc[m];
  inputarr(bc, m);
  sort(bc, bc + m, [&](pii a, pii b) { return a.se > b.se; });
  vi c;
  for (int i = 0; i < m; ++i) {
    while (sz(c) < n && bc[i].fi > 0) {
      bc[i].fi--;
      c.pb(bc[i].se);
    }
  }
  sort(a, a + n);
  for (int i = 0; i < n; ++i) {
    if (a[i] < c[i]) {
      a[i] = c[i];
    }
  }
  cout << accumulate(a, a + n, 0ll) << endl;
}
signed main() {
  FAST;
  int testcases = 1;
  // cin>>testcases;
  for (int i = 0; i < testcases; ++i) {
    meowmeow321();
  }
  cerr << endl << "Time Elasped : " << elasped_time << endl;
  return 0;
}

Fixed submission:
// #pragma GCC optimize("Ofast")
// #pragma GCC
// target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
// #pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define FAST                                                                   \
  std::ios_base::sync_with_stdio(false);                                       \
  cin.tie(0);                                                                  \
  cout.tie(0);
#define DECIMAL(n)                                                             \
  std::cout << std::fixed;                                                     \
  std::cout << std::setprecision(n);
#define hell 1000000007
#define narak 998244353
#define PI 3.14159265358979323844
#define mp make_pair
#define eb emplace_back
#define pb push_back
#define fi first
#define se second
#define all(v) v.begin(), v.end()
#define endl "\n"
#define sqr(a) (a) * (a)
#define __lcm(m, n) m *(n / __gcd(m, n))
#define inputarr(a, n)                                                         \
  for (int xxx = 0; xxx < n; ++xxx)                                            \
  cin >> (a)[xxx]
#define sz(a) (int)a.size()
#define sl(a) (int)a.length()
#define display(x)                                                             \
  for (auto &a : x)                                                            \
    cout << a << " ";                                                          \
  cout << endl
#define debug cerr << "bhau" << endl
#define between(n, a, b) (a <= n && n <= b)
#define elasped_time 1.0 * clock() / CLOCKS_PER_SEC

#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1> void __f(const char *name, Arg1 &&arg1) {
  std::cerr << name << " : " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char *names, Arg1 &&arg1, Args &&...args) {
  const char *comma = strchr(names + 1, ',');
  std::cerr.write(names, comma - names) << " : " << arg1 << " | ";
  __f(comma + 1, args...);
}

template <typename T, typename U> static inline void amin(T &x, U y) {
  if (y < x)
    x = y;
}

template <typename T, typename U> static inline void amax(T &x, U y) {
  if (x < y)
    x = y;
}

template <typename T, typename U>
std::ostream &operator<<(std::ostream &out, std::pair<T, U> a) {
  out << a.fi << " " << a.se;
  return out;
}

template <typename T, typename U>
std::istream &operator>>(std::istream &in, std::pair<T, U> &a) {
  in >> a.fi >> a.se;
  return in;
}

inline long long toint(const std::string &s) {
  std::stringstream ss;
  ss << s;
  long long x;
  ss >> x;
  return x;
}
inline std::string tostring(long long number) {
  std::stringstream ss;
  ss << number;
  return ss.str();
}
inline std::string tobin(long long x) { return std::bitset<63>(x).to_string(); }

std::mt19937_64
    rng(std::chrono::steady_clock::now().time_since_epoch().count());

#define ll long long
#define pii std::pair<int, int>
#define vi vector<int>
#define vvi vector<vi>
#define vii vector<pii>
#define point complex<ll>
#define ordered_set                                                            \
  tree<int, null_type, less<int>, rb_tree_tag,                                 \
       tree_order_statistics_node_update>

/*----------------------Graph Moves----------------*/
// const int fx[]={+1,-1,+0,+0};
// const int fy[]={+0,+0,+1,-1};
// const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
// const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
// const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
// const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

// primes for hashing 937,991,1013,1409,1741

using namespace std;
using namespace __gnu_pbds;
#define int long long
void meowmeow321() {
  int n, m;
  cin >> n >> m;
  int a[n];
  inputarr(a, n);
  pii bc[m];
  inputarr(bc, m);
  sort(bc, bc + m, [&](pii a, pii b) { return a.se > b.se; });
  vi c;
  for (int i = 0; i < m; ++i) {
    while (sz(c) < n && bc[i].fi > 0) {
      bc[i].fi--;
      c.pb(bc[i].se);
    }
  }
  sort(a, a + n);
  for (int i = 0; i < n && i < sz(c); ++i) {
    if (a[i] < c[i]) {
      a[i] = c[i];
    }
  }
  cout << accumulate(a, a + n, 0ll) << endl;
}
signed main() {
  FAST;
  int testcases = 1;
  // cin>>testcases;
  for (int i = 0; i < testcases; ++i) {
    meowmeow321();
  }
  cerr << endl << "Time Elasped : " << elasped_time << endl;
  return 0;
}