Problem p03102 (C++)

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

/*https://github.com/kurokoji/.cpp-Template/wiki#struct-fast*/
// 理解できていないものはコメントアウト
struct Fast {
  Fast() {
    std::cin.tie(0);
    ios::sync_with_stdio(false);
  }
} fast;

/* debug */
#define debug(x)                                                               \
  cerr << x << " "                                                             \
       << "(L:" << __LINE__ << ")" << '\n';

/* short */
// #define pb push_back
// #define eb emplace_back
// #define mp make_pair
// #define Fi first
// #define Se second
#define ALL(v) begin(v), end(v) // sort(ALL(v));みたいに使う
// #define RALL(v) rbegin(v), rend(v)
#define X real()
#define Y imag()

/* REPmacro */
#define REPS(i, a, n) for (ll i = (a); i < (ll)(n); ++i)
#define REP(i, n) REPS(i, 0, n)
#define RREP(i, n) REPS(i, 1, n + 1)
#define DEPS(i, a, n) for (ll i = (a); i >= (ll)(n); --i)
#define DEP(i, n) DEPS(i, n, 0)
// #define EACH(i, n) for (auto&& i : n)

/* alias */
using ll = long long;
using ull = unsigned long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
// using pii = pair<int, int>;
using D = double;
// using P = complex<D>;
using vs = vector<string>;
// template <typename T> using PQ = priority_queue<T>;
// template <typename T> using minPQ = priority_queue<T, vector<T>, greater<T>>;

/* const */
const int INF = 1001001001;
const ll LINF = 1001001001001001001ll;
const int MOD = 1e9 + 7;
const D EPS = 1e-9;
// const int dx[] = { 0, 1, 0, -1, 1, -1, 1, -1 }, dy[] = { 1, 0, -1, 0, 1, -1,
// -1, 1 };

/* func */
inline bool inside(int y, int x, int H, int W) {
  return y >= 0 && x >= 0 && y < H && x < W;
}
inline int in() {
  int x;
  cin >> x;
  return x;
}
// inline vs split(const string& t, char c) { vs v; stringstream s(t); string b;
// while (getline(s, b, c)) v.eb(b); return v; } template <typename T> inline
// bool chmin(T& a, const T& b) { if (a > b) a = b; return a > b; } template
// <typename T> inline bool chmax(T& a, const T& b) { if (a < b) a = b; return a
// < b; } template <typename T, typename S> inline void print(const pair<T, S>&
// p) { cout << p.first << " " << p.second << endl; }
template <typename T> inline void print(const T &x) { cout << x << '\n'; }
// template <typename T, typename S> inline void print(const vector<pair<T, S>>&
// v) { for (auto&& p : v) print(p); } template <typename T> inline void
// print(const vector<T>& v, string s = " ") { REP(i, v.size()) cout << v[i] <<
// (i != (ll)v.size() - 1 ? s : "\n"); }

// #define int long long

signed main() {
  int N, M, C;

  cin >> N >> M >> C;

  vi B;
  vvi A;

  for (int i = 0; i < M; ++i)
    B[i] = in();
  for (int j = 0; j < N; ++j)
    for (int k = 0; k < M; ++k)
      A[j][k] = in();

  int ans = 0;

  for (int j = 0; j < N; ++j) {
    ll sum = 0;

    for (int k = 0; k < M; ++k)
      sum += A[j][k] * B[k];

    if (sum + C > 0)
      ans++;
  }

  cout << ans << endl;

#ifdef _DEBUG
  system("pause");
#endif
  return 0;
}


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

/*https://github.com/kurokoji/.cpp-Template/wiki#struct-fast*/
// 理解できていないものはコメントアウト
struct Fast {
  Fast() {
    std::cin.tie(0);
    ios::sync_with_stdio(false);
  }
} fast;

/* debug */
#define debug(x)                                                               \
  cerr << x << " "                                                             \
       << "(L:" << __LINE__ << ")" << '\n';

/* short */
// #define pb push_back
// #define eb emplace_back
// #define mp make_pair
// #define Fi first
// #define Se second
#define ALL(v) begin(v), end(v) // sort(ALL(v));みたいに使う
// #define RALL(v) rbegin(v), rend(v)
#define X real()
#define Y imag()

/* REPmacro */
#define REPS(i, a, n) for (ll i = (a); i < (ll)(n); ++i)
#define REP(i, n) REPS(i, 0, n)
#define RREP(i, n) REPS(i, 1, n + 1)
#define DEPS(i, a, n) for (ll i = (a); i >= (ll)(n); --i)
#define DEP(i, n) DEPS(i, n, 0)
// #define EACH(i, n) for (auto&& i : n)

/* alias */
using ll = long long;
using ull = unsigned long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
// using pii = pair<int, int>;
using D = double;
// using P = complex<D>;
using vs = vector<string>;
// template <typename T> using PQ = priority_queue<T>;
// template <typename T> using minPQ = priority_queue<T, vector<T>, greater<T>>;

/* const */
const int INF = 1001001001;
const ll LINF = 1001001001001001001ll;
const int MOD = 1e9 + 7;
const D EPS = 1e-9;
// const int dx[] = { 0, 1, 0, -1, 1, -1, 1, -1 }, dy[] = { 1, 0, -1, 0, 1, -1,
// -1, 1 };

/* func */
inline bool inside(int y, int x, int H, int W) {
  return y >= 0 && x >= 0 && y < H && x < W;
}
inline int in() {
  int x;
  cin >> x;
  return x;
}
// inline vs split(const string& t, char c) { vs v; stringstream s(t); string b;
// while (getline(s, b, c)) v.eb(b); return v; } template <typename T> inline
// bool chmin(T& a, const T& b) { if (a > b) a = b; return a > b; } template
// <typename T> inline bool chmax(T& a, const T& b) { if (a < b) a = b; return a
// < b; } template <typename T, typename S> inline void print(const pair<T, S>&
// p) { cout << p.first << " " << p.second << endl; }
template <typename T> inline void print(const T &x) { cout << x << '\n'; }
// template <typename T, typename S> inline void print(const vector<pair<T, S>>&
// v) { for (auto&& p : v) print(p); } template <typename T> inline void
// print(const vector<T>& v, string s = " ") { REP(i, v.size()) cout << v[i] <<
// (i != (ll)v.size() - 1 ? s : "\n"); }

// #define int long long

signed main() {
  int N, M, C;

  cin >> N >> M >> C;

  vi B;
  vvi A;

  B = vector<int>(M, 0);
  A = vector<vector<int>>(N, vector<int>(M, 0));

  for (int i = 0; i < M; ++i)
    B[i] = in();
  for (int j = 0; j < N; ++j)
    for (int k = 0; k < M; ++k)
      A[j][k] = in();

  int ans = 0;

  for (int j = 0; j < N; ++j) {
    ll sum = 0;

    for (int k = 0; k < M; ++k)
      sum += A[j][k] * B[k];

    if (sum + C > 0)
      ans++;
  }

  cout << ans << endl;

#ifdef _DEBUG
  system("pause");
#endif
  return 0;
}