Problem p02854 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstdio>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_set>
#include <vector>
using namespace std;
typedef long double ld;
typedef long long int ll;
typedef unsigned long long int ull;
typedef vector<int> vi;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef vector<string> vs;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpii;
typedef vector<vector<int>> vvi;
typedef vector<vector<char>> vvc;
typedef vector<vector<string>> vvs;
typedef vector<vector<ll>> vvll;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i <= (n); ++i)
#define drep(i, n) for (int i = (n)-1; i >= 0; --i)
#define fin(ans) cout << (ans) << endl
#define STI(s) atoi(s.c_str())
#define mp(p, q) make_pair(p, q)
#define pb(n) push_back(n)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define Sort(a) sort(a.begin(), a.end())
#define Rort(a) sort(a.rbegin(), a.rend())
#define MATHPI acos(-1)
#define itn int
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
struct io {
  io() {
    ios::sync_with_stdio(false);
    cin.tie(0);
  };
};
const ll MOD = 1000000007;
const int INF = INT_MAX;
const ll LLINF = 1LL << 62;

int main(void) {

  int n;
  cin >> n;
  vll v(n);
  rep(i, n) cin >> v[i];
  ll ans = LLINF;
  for (int i = 0; i < n - 1; i++) {
    ll a = 0, b = 0;
    for (int j = 0; j <= i; j++)
      a += v[j];
    for (int j = i + 1; j < n; j++)
      b += v[j];
    ans = min(ans, abs(a - b));
  }
  fin(ans);
}


Fixed submission:
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstdio>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_set>
#include <vector>
using namespace std;
typedef long double ld;
typedef long long int ll;
typedef unsigned long long int ull;
typedef vector<int> vi;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef vector<string> vs;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpii;
typedef vector<vector<int>> vvi;
typedef vector<vector<char>> vvc;
typedef vector<vector<string>> vvs;
typedef vector<vector<ll>> vvll;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i <= (n); ++i)
#define drep(i, n) for (int i = (n)-1; i >= 0; --i)
#define fin(ans) cout << (ans) << endl
#define STI(s) atoi(s.c_str())
#define mp(p, q) make_pair(p, q)
#define pb(n) push_back(n)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define Sort(a) sort(a.begin(), a.end())
#define Rort(a) sort(a.rbegin(), a.rend())
#define MATHPI acos(-1)
#define itn int
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
struct io {
  io() {
    ios::sync_with_stdio(false);
    cin.tie(0);
  };
};
const ll MOD = 1000000007;
const int INF = INT_MAX;
const ll LLINF = 1LL << 62;

int main(void) {

  int n;
  cin >> n;
  vll v(n);
  rep(i, n) cin >> v[i];
  ll ans = LLINF;
  ll a = v[0];
  ll b = 0;
  for (int i = 1; i < n; i++)
    b += v[i];
  ans = min(ans, abs(a - b));
  for (int i = 1; i < n - 1; i++) {
    a += v[i];
    b -= v[i];
    ans = min(ans, abs(a - b));
  }
  fin(ans);
}