Problem p03162 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;

#define ff first
#define ss second
#define int long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define vi vector<int>
#define mii map<int, int>
#define pqb priority_queue<int>
#define pqs priority_queue<int, vi, greater<int>>
#define setbits(x) __builtin_popcountll(x)
#define zrobits(x) __builtin_ctzll(x)
#define mod 1000000007
#define inf 1e18
#define ps(x, y) fixed << setprecision(y) << x
#define mk(arr, n, type) type *arr = new type[n];
#define w(x)                                                                   \
  int x;                                                                       \
  cin >> x;                                                                    \
  while (x--)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

typedef tree<int, null_type, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    pbds;

void dk() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif
}

int32_t main() {
  dk();
  int n;
  cin >> n;
  int a[3];
  int dp[3];
  int t[3];
  memset(dp, 0, sizeof dp);
  memset(t, 0, sizeof t);
  for (int i = 0; i < n; i++) {
    cin >> a[0] >> a[1] >> a[2];
    for (int k = 0; k < 3; k++) {
      for (int j = 0; j < 3; j++) {
        if (k != j) {
          t[j] = max(t[j], dp[k] + a[j]);
        }
      }
    }
    dp[0] = t[0];
    dp[1] = t[1];
    dp[2] = t[2];
  }
  cout << max(dp[0], max(dp[1], dp[2]));
  return 0;
}

Fixed submission:
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;

#define ff first
#define ss second
#define int long long
#define pb push_back
#define mp make_pair
#define pii pair<int, int>
#define vi vector<int>
#define mii map<int, int>
#define pqb priority_queue<int>
#define pqs priority_queue<int, vi, greater<int>>
#define setbits(x) __builtin_popcountll(x)
#define zrobits(x) __builtin_ctzll(x)
#define mod 1000000007
#define inf 1e18
#define ps(x, y) fixed << setprecision(y) << x
#define mk(arr, n, type) type *arr = new type[n];
#define w(x)                                                                   \
  int x;                                                                       \
  cin >> x;                                                                    \
  while (x--)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

typedef tree<int, null_type, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    pbds;

void dk() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif
}

int32_t main() {
  // dk();
  int n;
  cin >> n;
  int a[3];
  int dp[3];
  int t[3];
  memset(dp, 0, sizeof dp);
  memset(t, 0, sizeof t);
  for (int i = 0; i < n; i++) {
    cin >> a[0] >> a[1] >> a[2];
    for (int k = 0; k < 3; k++) {
      for (int j = 0; j < 3; j++) {
        if (k != j) {
          t[j] = max(t[j], dp[k] + a[j]);
        }
      }
    }
    dp[0] = t[0];
    dp[1] = t[1];
    dp[2] = t[2];
  }
  cout << max(dp[0], max(dp[1], dp[2]));
  return 0;
}