Problem p03510 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <assert.h>
#include <bitset>
#include <cmath>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits.h>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <time.h>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#pragma warning(disable : 4996)
#pragma comment(linker, "/STACK:336777216")
using namespace std;

#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define ldb ldouble

typedef tuple<int, int, int> t3;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ldb;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ll, int> pli;
typedef pair<db, db> pdd;

int IT_MAX = 1 << 18;
int MOD = 1000000007;
const int INF = 0x3f3f3f3f;
const ll LL_INF = 0x3f3f3f3f3f3f3f3f;
const db PI = acos(-1);
const db ERR = 1e-10;
#define szz(x) (int)(x).size()
#define rep(i, n) for (int i = 0; i < n; i++)
#define Se second
#define Fi first

const int MX = 100005;
const int MM = 1000000007;

ll A[MX], B[MX];
int N;

ll DnC(int s, int e) {
  if (s > e)
    return 0;
  if (s == e)
    return B[s];
  int m = (s + e) / 2;
  ll l = 0, total = 0, r = 0;
  for (int i = m; i >= s; i--) {
    total += B[i];
    l = max(l, total - A[m] + A[i]);
  }
  total = 0;
  for (int i = m; i <= e; i++) {
    total += B[i];
    r = max(r, total - A[i] + A[m]);
  }
  return max({DnC(s, m - 1), DnC(m + 1, e), l + r - B[m]});
}

int main() {
  scanf("%d", &N);
  for (int i = 1; i <= N; i++)
    scanf("%lld%lld", A + i, B + i);
  printf("%lld\n", DnC(1, N));
}


Fixed submission:
#include <algorithm>
#include <assert.h>
#include <bitset>
#include <cmath>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits.h>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <time.h>
#include <unordered_map>
#include <unordered_set>
#include <vector>

#pragma warning(disable : 4996)
#pragma comment(linker, "/STACK:336777216")
using namespace std;

#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define ldb ldouble

typedef tuple<int, int, int> t3;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ldb;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ll, int> pli;
typedef pair<db, db> pdd;

int IT_MAX = 1 << 18;
int MOD = 1000000007;
const int INF = 0x3f3f3f3f;
const ll LL_INF = 0x3f3f3f3f3f3f3f3f;
const db PI = acos(-1);
const db ERR = 1e-10;
#define szz(x) (int)(x).size()
#define rep(i, n) for (int i = 0; i < n; i++)
#define Se second
#define Fi first

const int MX = 200005;
const int MM = 1000000007;

ll A[MX], B[MX];
int N;

ll DnC(int s, int e) {
  if (s > e)
    return 0;
  if (s == e)
    return B[s];
  int m = (s + e) / 2;
  ll l = 0, total = 0, r = 0;
  for (int i = m; i >= s; i--) {
    total += B[i];
    l = max(l, total - A[m] + A[i]);
  }
  total = 0;
  for (int i = m; i <= e; i++) {
    total += B[i];
    r = max(r, total - A[i] + A[m]);
  }
  return max({DnC(s, m - 1), DnC(m + 1, e), l + r - B[m]});
}

int main() {
  scanf("%d", &N);
  for (int i = 1; i <= N; i++)
    scanf("%lld%lld", A + i, B + i);
  printf("%lld\n", DnC(1, N));
}