Problem p02623 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;
#define ull unsigned long long
#define MOD (int)(1e9 + 7)
#define ceil(x, y) (x % y == 0 ? (x / y) : (x / y + 1))
#define FOR(i, N) for (int i = 0; i < N; ++i)
#define FOR1(i, N) for (int i = 1; i <= N; ++i)
#define vi vector<int>
#define pii pair<int, int>
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define mset(a, v) memset(a, v, sizeof(a))
#define all(v) (v).begin(), (v).end()
#define INF 2e9
#define EPS 1e-9
#define MAX 200009
#define int long long
/*#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
typedef cc_hash_table<int, int, hash<int>> ht; // while using, comment #define
int long long  */

void __print(int x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\\'' << x << '\\''; }
void __print(const char *x) { cerr << '\\"' << x << '\\"'; }
void __print(const string &x) { cerr << '\\"' << x << '\\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifndef ONLINE_JUDGE
#define dbg(x...)                                                              \\
  cerr << "[" << #x << "] = [";                                                \\
  _print(x)
#else
#define dbg(x...)
#endif
using namespace std;
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
#ifndef ONLINE_JUDGE
  freopen("in.txt", "r", stdin);
  freopen("out.txt", "w", stdout);
#endif

  int T = 1;
  // cin >> T;
  FOR1(tt, T) {
    // cout << "Case #" << tp << ": ";
    int n, m, k;
    cin >> n >> m >> k;
    int a[n + 1];
    a[0] = 0;
    FOR1(i, n) cin >> a[i];
    int b[m + 1];
    b[0] = 0;
    FOR1(i, m) cin >> b[i];

    int pre_a[n + 1];
    pre_a[0] = 0;
    int pre_b[m + 1];
    pre_b[0] = 0;
    FOR1(i, n) { pre_a[i] = pre_a[i - 1] + a[i]; }
    FOR1(i, m) { pre_b[i] = pre_b[i - 1] + b[i]; }
    int ans = 0;
    for (int i = 0; i <= n; i++) {

      int j = upper_bound(pre_b + 1, pre_b + m + 1, k - pre_a[i]) - 1 - pre_b;
      dbg(tt, i, j, i + j);
      if (pre_a[i] + pre_b[j] <= k)
        ans = max(ans, i + j);
    }
    cout << ans;
    cout << '\\n';
  }
  return 0;
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
#define ull unsigned long long
#define MOD (int)(1e9 + 7)
#define ceil(x, y) (x % y == 0 ? (x / y) : (x / y + 1))
#define FOR(i, N) for (int i = 0; i < N; ++i)
#define FOR1(i, N) for (int i = 1; i <= N; ++i)
#define vi vector<int>
#define pii pair<int, int>
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define mset(a, v) memset(a, v, sizeof(a))
#define all(v) (v).begin(), (v).end()
#define INF 2e9
#define EPS 1e-9
#define MAX 200009
#define int long long
/*#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
typedef cc_hash_table<int, int, hash<int>> ht; // while using, comment #define
int long long  */

void __print(int x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\\'' << x << '\\''; }
void __print(const char *x) { cerr << '\\"' << x << '\\"'; }
void __print(const string &x) { cerr << '\\"' << x << '\\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifndef ONLINE_JUDGE
#define dbg(x...)                                                              \\
  cerr << "[" << #x << "] = [";                                                \\
  _print(x)
#else
#define dbg(x...)
#endif
using namespace std;
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
#ifndef ONLINE_JUDGE
  freopen("in.txt", "r", stdin);
  freopen("out.txt", "w", stdout);
#endif

  int T = 1;
  // cin >> T;
  FOR1(tp, T) {
    // cout << "Case #" << tp << ": ";
    int n, m, k;
    cin >> n >> m >> k;
    int a[n + 1];
    a[0] = 0;
    FOR1(i, n) cin >> a[i];
    int b[m + 1];
    b[0] = 0;
    FOR1(i, m) cin >> b[i];

    int ans = 0;

    int a_sum = 0;
    FOR(i, n + 1) {
      a_sum += a[i];
      int b_sum = 0;
      FOR(j, m + 1) {
        b_sum += b[j];
        // dbg(a[i], b[j], a_sum+b_sum);
        if (a_sum + b_sum <= k) {
          ans = max(ans, i + j);
        }
      }
    }

    cout << ans;
    cout << '\\n';
  }
  return 0;
}