Problem p02623 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ld long double

#define rep(i, a, b) for (int i = a; i < b; i++)
#define repb(i, a, b) for (int i = a; i > b; i--)

#define pb push_back
#define mp make_pair
#define all(A) A.begin(), A.end()
#define allr(A) A.rbegin(), A.rend()
#define precise(i) fixed << setprecision(i)
#define fi first
#define se second

#define err() cout << "\\n==================================\\n";
#define errA(A)                                                                \\
  for (auto i : A)                                                             \\
    cout << i << " ";                                                          \\
  cout << "\\n";
#define err1(a) cout << #a << " " << a << "\\n";
#define err2(a, b) cout << #a << " " << a << " " << #b << " " << b << "\\n";
#define err3(a, b, c)                                                          \\
  cout << #a << " " << a << " " << #b << " " << b << " " << #c << " " << c     \\
       << "\\n";
#define err4(a, b, c, d)                                                       \\
  cout << #a << " " << a << " " << #b << " " << b << " " << #c << " " << c     \\
       << " " << #d << " " << d << "\\n";

const int logN = 20;
const int M = 1000000007;
const int INF = 1e12;
#define PI 3.14159265;
const int N = 200005;

#define Pii pair<int, int>
#define Vi vector<int>
#define Vpii vector<Pii>

void solve() {
  int n, m, k, tot = 0, num = 0, best = -1;
  cin >> n >> m >> k;
  int p1 = -1, p2 = 0;
  int a[n], b[m];
  rep(c, 0, n) { cin >> a[c]; }
  rep(c, 0, m) { cin >> b[c]; }
  rep(c, 0, n) {
    if ((tot + a[c]) <= k) {
      tot += a[c];
      num++;
      p1 = c;
    } else {
      break;
    }
  }
  while (p1 >= -1) {
    while ((p2 < m) && ((tot + b[p2]) <= k)) {
      tot += b[p2++];
      num++;
    }
    best = max(num, best);
    if (p1 == -1) {
      break;
    }
    tot -= a[p1];
    p1--;
    num--;
  }
  cout << best;
}

int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  //    cin>>t;
  while (t--) {
    solve();
  }
  return 0;
}

Error: WA

Fixed submission:

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ld long double

#define rep(i, a, b) for (int i = a; i < b; i++)
#define repb(i, a, b) for (int i = a; i > b; i--)

#define pb push_back
#define mp make_pair
#define all(A) A.begin(), A.end()
#define allr(A) A.rbegin(), A.rend()
#define precise(i) fixed << setprecision(i)
#define fi first
#define se second

#define err() cout << "\\n==================================\\n";
#define errA(A)                                                                \\
  for (auto i : A)                                                             \\
    cout << i << " ";                                                          \\
  cout << "\\n";
#define err1(a) cout << #a << " " << a << "\\n";
#define err2(a, b) cout << #a << " " << a << " " << #b << " " << b << "\\n";
#define err3(a, b, c)                                                          \\
  cout << #a << " " << a << " " << #b << " " << b << " " << #c << " " << c     \\
       << "\\n";
#define err4(a, b, c, d)                                                       \\
  cout << #a << " " << a << " " << #b << " " << b << " " << #c << " " << c     \\
       << " " << #d << " " << d << "\\n";

const int logN = 20;
const int M = 1000000007;
const int INF = 1e12;
#define PI 3.14159265;
const int N = 200005;

#define Pii pair<int, int>
#define Vi vector<int>
#define Vpii vector<Pii>

void solve() {
  int n, m, k, tot = 0, num = 0, best = -1;
  cin >> n >> m >> k;
  int p1;
  int a[n], b[m];
  rep(c, 0, n) { cin >> a[c]; }
  rep(c, 0, m) { cin >> b[c]; }
  rep(c, 0, n) {
    if ((tot + a[c]) <= k) {
      tot += a[c];
      num++;
      p1 = c;
    } else {
      break;
    }
  }
  while (p1 >= -1) {
    rep(c, 0, m) {
      if ((tot + b[c]) <= k) {
        tot += b[c];
        num++;
      } else {
        break;
      }
    }
    best = max(num, best);
    if (p1 == -1) {
      break;
    }
    tot -= a[p1];
    p1--;
    num--;
  }
  cout << best;
}

int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t = 1;
  //    cin>>t;
  while (t--) {
    solve();
  }
  return 0;
}