Problem p03163 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;
#define fastio()                                                               \
  ios_base::sync_with_stdio(0);                                                \
  cin.tie(0);                                                                  \
  cout.tie(0)
#define pb push_back
#define show(x) cout << (#x) << " : " << x << endl;
#define ll long long
#define int long long
#define ld long double
#define fill(a, val) memset(a, val, sizeof(a))
#define mp make_pair
#define ff first
#define ss second
#define pii pair<ll, ll>
#define sq(x) ((x) * (x))
#define all(v) v.begin(), v.end()
#define fone for (i = 0; i < n; i++)
#define endl "\n"
const ll MOD = 1000 * 1000 * 1000 + 7;
const ll INF = 1ll * 1000 * 1000 * 1000 * 1000 * 1000 * 1000 + 7;
const ll MOD2 = 998244353;
const ll N = 5000 * 100 + 1;
const ll N2 = 1000 * 1000 + 5;
const ld PI = 3.14159265;
const ll R = 250;
ll gcd(ll a, ll b) {
  if (!b)
    return a;
  return gcd(b, a % b);
}
ll power(ll x, ll y, ll p) {
  ll res = 1;
  x %= p;
  while (y > 0) {
    if (y & 1)
      res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
bool sortbysec(const pair<int, int> &a, const pair<int, int> &b) {
  return (a.second < b.second);
}

signed main() {
  fastio();
  int n, k, W;
  vector<pair<int, int>> vv;
  cin >> n >> W;

  int v[n], w[n];
  for (int i = 0; i < n; i++) {
    cin >> w[i] >> v[i];
  }

  // cout<<"*";
  vector<vector<ll>> dp(N + 1, vector<ll>(W + 1, 0LL));
  // int dp[1000][1000];
  for (int i = 1; i <= n; i++) {
    for (int j = 0; j <= W; j++) {
      if (j - w[i - 1] < 0)
        dp[i][j] = dp[i - 1][j];
      else
        dp[i][j] = max(dp[i - 1][j], dp[i - 1][j - w[i - 1]] + v[i - 1]);
    }
  }
  ll ans = 0;
  for (int j = 0; j <= W; j++) {
    ans = max(ans, dp[n][j]);
  }

  cout << ans << endl;

  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;
#define fastio()                                                               \
  ios_base::sync_with_stdio(0);                                                \
  cin.tie(0);                                                                  \
  cout.tie(0)
#define pb push_back
#define show(x) cout << (#x) << " : " << x << endl;
#define ll long long
#define int long long
#define ld long double
#define fill(a, val) memset(a, val, sizeof(a))
#define mp make_pair
#define ff first
#define ss second
#define pii pair<ll, ll>
#define sq(x) ((x) * (x))
#define all(v) v.begin(), v.end()
#define fone for (i = 0; i < n; i++)
#define endl "\n"
const ll MOD = 1000 * 1000 * 1000 + 7;
const ll INF = 1ll * 1000 * 1000 * 1000 * 1000 * 1000 * 1000 + 7;
const ll MOD2 = 998244353;
const ll N = 5000 * 100 + 1;
const ll N2 = 1000 * 1000 + 5;
const ld PI = 3.14159265;
const ll R = 250;
ll gcd(ll a, ll b) {
  if (!b)
    return a;
  return gcd(b, a % b);
}
ll power(ll x, ll y, ll p) {
  ll res = 1;
  x %= p;
  while (y > 0) {
    if (y & 1)
      res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
bool sortbysec(const pair<int, int> &a, const pair<int, int> &b) {
  return (a.second < b.second);
}

signed main() {
  fastio();
  int n, k, W;
  vector<pair<int, int>> vv;
  cin >> n >> W;

  int v[n], w[n];
  for (int i = 0; i < n; i++) {
    cin >> w[i] >> v[i];
  }

  // cout<<"*";
  vector<vector<ll>> dp(n + 1, vector<ll>(W + 1, 0LL));
  // int dp[1000][1000];
  for (int i = 1; i <= n; i++) {
    for (int j = 0; j <= W; j++) {
      if (j - w[i - 1] < 0)
        dp[i][j] = dp[i - 1][j];
      else
        dp[i][j] = max(dp[i - 1][j], dp[i - 1][j - w[i - 1]] + v[i - 1]);
    }
  }
  ll ans = 0;
  for (int j = 0; j <= W; j++) {
    ans = max(ans, dp[n][j]);
  }

  cout << ans << endl;

  return 0;
}