Problem p01140 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef tuple<int, int> duo;
const int dx[] = {0, 0, 1, -1, 1, 1, -1, -1};
const int dy[] = {1, -1, 0, 0, 1, -1, 1, -1};
const int Mod = 1000000000 + 0;
//{{{ templates
#define TT_ template <typename T> inline
#define TTF_ template <typename T, typename F> inline
TT_ T sq(T x) { return x * x; }
TT_ T In() {
  T x;
  cin >> x;
  return x;
}
TT_ void Out(T &x) { cout << x; }
TT_ void sort(T &v) { sort(begin(v), end(v)); }
TT_ void revs(T &v) { reverse(begin(v), end(v)); }
TT_ void uniq(T &v) {
  sort(v);
  v.erase(unique(begin(v), end(v)), end(v));
}
TT_ int ubnd(T &v, typename T::value_type x) {
  return upper_bound(begin(v), end(v), x) - begin(v);
}
TT_ int lbnd(T &v, typename T::value_type x) {
  return lower_bound(begin(v), end(v), x) - begin(v);
}
TTF_ void inpt(T &v, int n, F f) {
  for (v.reserve(n); n--; v.emplace_back(f()))
    ;
}
TTF_ void show(T &v, F f, string d = " ", string e = "\n") {
  int i = 0;
  for (auto &x : v)
    i++ && (cout << d), f(x);
  cout << e;
}
TT_ typename T::iterator minel(T &v) { return min_element(begin(v), end(v)); }
TT_ typename T::iterator maxel(T &v) { return max_element(begin(v), end(v)); }

inline void fast_io() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
}
inline int in() {
  int x;
  scanf("%d", &x);
  return x;
}
inline ll pow_mod(ll a, ll k, ll m) {
  ll r = 1;
  for (; k > 0; a = a * a % m, k >>= 1)
    if (k & 1)
      r = r * a % m;
  return r;
}
inline ll mod_inv(ll a, ll p) { return pow_mod(a, p - 2, p); }
//}}} priority_queue queue deque front stringstream max_element min_element
//insert count make_tuple

short B[3000300];
int H[2048], W[2048];
int main() {
  int N, M;
  short K = 0;
  while (N = in(), M = in()) {
    K++;
    for (int i = 1; i <= N; i++) {
      H[i] = H[i - 1] + in();
      B[H[i]] = K;
    }
    for (int i = 1; i <= M; i++) {
      W[i] = W[i - 1] + in();
    }
    int ans = 0;
    for (int y = 0, y_ = N; y < y_; y++) {
      const int hy = H[y];
      for (int x = 0, x_ = M; x < x_; x++) {
        const int wx = W[x];
        for (int z = x + 1, z_ = M; z <= z_; z++) {
          int d = W[z] - wx;
          ans += B[hy + d] == K;
        }
      }
    }
    printf("%d\n", ans);
  }
  return 0;
}

Fixed submission:
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef tuple<int, int> duo;
const int dx[] = {0, 0, 1, -1, 1, 1, -1, -1};
const int dy[] = {1, -1, 0, 0, 1, -1, 1, -1};
const int Mod = 1000000000 + 0;
//{{{ templates
#define TT_ template <typename T> inline
#define TTF_ template <typename T, typename F> inline
TT_ T sq(T x) { return x * x; }
TT_ T In() {
  T x;
  cin >> x;
  return x;
}
TT_ void Out(T &x) { cout << x; }
TT_ void sort(T &v) { sort(begin(v), end(v)); }
TT_ void revs(T &v) { reverse(begin(v), end(v)); }
TT_ void uniq(T &v) {
  sort(v);
  v.erase(unique(begin(v), end(v)), end(v));
}
TT_ int ubnd(T &v, typename T::value_type x) {
  return upper_bound(begin(v), end(v), x) - begin(v);
}
TT_ int lbnd(T &v, typename T::value_type x) {
  return lower_bound(begin(v), end(v), x) - begin(v);
}
TTF_ void inpt(T &v, int n, F f) {
  for (v.reserve(n); n--; v.emplace_back(f()))
    ;
}
TTF_ void show(T &v, F f, string d = " ", string e = "\n") {
  int i = 0;
  for (auto &x : v)
    i++ && (cout << d), f(x);
  cout << e;
}
TT_ typename T::iterator minel(T &v) { return min_element(begin(v), end(v)); }
TT_ typename T::iterator maxel(T &v) { return max_element(begin(v), end(v)); }

inline void fast_io() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
}
inline int in() {
  int x;
  scanf("%d", &x);
  return x;
}
inline ll pow_mod(ll a, ll k, ll m) {
  ll r = 1;
  for (; k > 0; a = a * a % m, k >>= 1)
    if (k & 1)
      r = r * a % m;
  return r;
}
inline ll mod_inv(ll a, ll p) { return pow_mod(a, p - 2, p); }
//}}} priority_queue queue deque front stringstream max_element min_element
//insert count make_tuple

short B[3000300];
int H[2048], W[2048];
int main() {
  int N, M;
  short K = 0;
  while (N = in(), M = in()) {
    K++;
    for (int i = 1; i <= N; i++) {
      H[i] = H[i - 1] + in();
      B[H[i]] = K;
    }
    for (int i = 1; i <= M; i++) {
      W[i] = W[i - 1] + in();
    }
    int ans = 0;
    for (int y = 0; y < N; y++) {
      for (int x = 0; x < M; x++) {
        for (int z = x + 1; z <= M; z++) {
          int d = W[z] - W[x];
          if (H[N] - H[y] < d)
            break;
          ans += B[H[y] + d] == K;
        }
      }
    }
    printf("%d\n", ans);
  }
  return 0;
}