Problem p01088 (C++)

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

// #define int long long
#define reps(i, s, n) for (int(i) = (s); (i) < (n); ++(i))
#define rep(i, n) reps(i, 0, n)
#define rept(i, n) rep(i, (n) + 1)
#define repst(i, s, n) reps(i, s, (n) + 1)
#define reprt(i, n, t) for (int(i) = (n); (i) >= (t); --(i))
#define repr(i, n) reprt(i, n, 0)
#define each(itr, v) for (auto &(itr) : (v))
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define tmax(x, y, z) max(x, max(y, z))
#define tmin(x, y, z) min(x, min(y, z))
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define ln '\n'
#define bln(i, n) (((i) == (n)-1) ? '\n' : ' ')
#define dbg(x) cout << #x " = " << (x) << ln << flush
#define dbga(x, n)                                                             \
  {                                                                            \
    cout << #x " : ";                                                          \
    for (int(i) = 0; i < (n); ++i) {                                           \
      cout << ((x)[i]) << (i == ((n)-1) ? '\n' : ' ') << flush;                \
    }                                                                          \
  }
#define zero(a) memset(a, 0, sizeof(a))
#define unq(a) sort(all(a)), a.erase(unique(all(a)), a.end())

typedef long double ld;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<string> vst;
typedef vector<bool> vb;
typedef vector<ld> vld;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vector<int>> mat;

const ll inf = (ll)1e9 + 10;
const ll linf = (ll)1e18 + 10;
const ll mod = (ll)(1e9 + 7);
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const int ddx[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int ddy[] = {1, 1, 0, -1, -1, -1, 0, 1};
const double eps = 1e-10;

ll mop(ll a, ll b, ll m = mod) {
  ll r = 1;
  a %= m;
  for (; b; b >>= 1) {
    if (b & 1)
      r = r * a % m;
    a = a * a % m;
  }
  return r;
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }
bool ool(int x, int y, int h, int w) {
  return ((x < 0) || (h <= x) || (y < 0) || (w <= y));
}

struct oreno_initializer {
  oreno_initializer() {
    cin.tie(0);
    ios::sync_with_stdio(0);
  }
} oreno_initializer;

// ━━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…
// .｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋
// ・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・

// dp[i][j]:
// i番目の店までで100円以下の小銭の総額がjとなるような買い方の{500円玉の枚数,-購入金額}の最大値
// 遷移は a)500円玉を得られるように買う b)1000円札のみで買って小銭を稼ぐ
// c)買わない bでも500円玉を得られる場合がある
int n, p[100];
pii dp[100][50050];

signed main() {
  while (1) {
    cin >> n;
    if (n == 0)
      break;
    rep(i, n) cin >> p[i];
    rept(i, n) rept(j, 50000) dp[i][j] = {-1, 0};
    dp[0][0] = {0, 0};
    rep(i, n) rept(j, 50000) if (dp[i][j].fi != -1) {
      int g = dp[i][j].fi, u = -dp[i][j].se;
      // 500円玉を得る
      if (j >= (p[i] + 500) % 1000)
        chmax(dp[i + 1][j - (p[i] + 500) % 1000], mp(g + 1, -(u + p[i])));
      // 1000円札のみ
      if (1 <= p[i] % 1000 && p[i] % 1000 <= 500)
        chmax(dp[i + 1][j + (500 - p[i] % 1000)], mp(g + 1, -(u + p[i])));
      if (500 < p[i] % 1000)
        chmax(dp[i + 1][j + (1000 - p[i] % 1000)], mp(g, -(u + p[i])));
      // 買わない
      chmax(dp[i + 1][j], mp(g, -u));
    }
    pii res = mp(0, 0);
    rept(i, 50000) chmax(res, dp[n][i]);
    cout << res.fi << ' ' << -res.se << ln;
  }
}


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

// #define int long long
#define reps(i, s, n) for (int(i) = (s); (i) < (n); ++(i))
#define rep(i, n) reps(i, 0, n)
#define rept(i, n) rep(i, (n) + 1)
#define repst(i, s, n) reps(i, s, (n) + 1)
#define reprt(i, n, t) for (int(i) = (n); (i) >= (t); --(i))
#define repr(i, n) reprt(i, n, 0)
#define each(itr, v) for (auto &(itr) : (v))
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define tmax(x, y, z) max(x, max(y, z))
#define tmin(x, y, z) min(x, min(y, z))
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define ln '\n'
#define bln(i, n) (((i) == (n)-1) ? '\n' : ' ')
#define dbg(x) cout << #x " = " << (x) << ln << flush
#define dbga(x, n)                                                             \
  {                                                                            \
    cout << #x " : ";                                                          \
    for (int(i) = 0; i < (n); ++i) {                                           \
      cout << ((x)[i]) << (i == ((n)-1) ? '\n' : ' ') << flush;                \
    }                                                                          \
  }
#define zero(a) memset(a, 0, sizeof(a))
#define unq(a) sort(all(a)), a.erase(unique(all(a)), a.end())

typedef long double ld;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<string> vst;
typedef vector<bool> vb;
typedef vector<ld> vld;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vector<int>> mat;

const ll inf = (ll)1e9 + 10;
const ll linf = (ll)1e18 + 10;
const ll mod = (ll)(1e9 + 7);
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const int ddx[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int ddy[] = {1, 1, 0, -1, -1, -1, 0, 1};
const double eps = 1e-10;

ll mop(ll a, ll b, ll m = mod) {
  ll r = 1;
  a %= m;
  for (; b; b >>= 1) {
    if (b & 1)
      r = r * a % m;
    a = a * a % m;
  }
  return r;
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }
bool ool(int x, int y, int h, int w) {
  return ((x < 0) || (h <= x) || (y < 0) || (w <= y));
}

struct oreno_initializer {
  oreno_initializer() {
    cin.tie(0);
    ios::sync_with_stdio(0);
  }
} oreno_initializer;

// ━━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…
// .｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋
// ・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・

// dp[i][j]:
// i番目の店までで100円以下の小銭の総額がjとなるような買い方の{500円玉の枚数,-購入金額}の最大値
// 遷移は a)500円玉を得られるように買う b)1000円札のみで買って小銭を稼ぐ
// c)買わない bでも500円玉を得られる場合がある
int n, p[100];
pii dp[101][50050];

signed main() {
  while (1) {
    cin >> n;
    if (n == 0)
      break;
    rep(i, n) cin >> p[i];
    rept(i, n) rept(j, 50000) dp[i][j] = {-1, 0};
    dp[0][0] = {0, 0};
    rep(i, n) rept(j, 50000) if (dp[i][j].fi != -1) {
      int g = dp[i][j].fi, u = -dp[i][j].se;
      // 500円玉を得る
      if (j >= (p[i] + 500) % 1000)
        chmax(dp[i + 1][j - (p[i] + 500) % 1000], mp(g + 1, -(u + p[i])));
      // 1000円札のみ
      if (1 <= p[i] % 1000 && p[i] % 1000 <= 500)
        chmax(dp[i + 1][j + (500 - p[i] % 1000)], mp(g + 1, -(u + p[i])));
      if (500 < p[i] % 1000)
        chmax(dp[i + 1][j + (1000 - p[i] % 1000)], mp(g, -(u + p[i])));
      // 買わない
      chmax(dp[i + 1][j], mp(g, -u));
    }
    pii res = mp(0, 0);
    rept(i, 50000) chmax(res, dp[n][i]);
    cout << res.fi << ' ' << -res.se << ln;
  }
}