Submission #37835

#	Time	Username	Problem	Language	Result	Execution time	Memory
37835		mirbek01	Divide and conquer (IZhO14_divide)	C++14	48 / 100	1000 ms	26352 KiB

divide

# include <bits/stdc++.h>

# define pb push_back
# define fr first
# define sc second
# define mk make_pair

using namespace std;

const int inf = 1e9 + 7;
const int N = 1e5 + 5;

typedef long long ll;

int n, a[N];
ll ans, b[N], c[N], cb[N], cc[N], s1, s2;
vector < pair <int, int> > t[N * 4];

void Merge(vector < pair <int, int> > a, vector < pair <int, int> > b, vector < pair <int, int> > &c)
{
      int i = 0, j = 0;
      while(i < a.size() && j < b.size())
            if(a[i] < b[j])
                  c.pb(a[i ++]);
            else
                  c.pb(b[j ++]);

      while(i < a.size())
            c.pb(a[i ++]);
      while(j < b.size())
            c.pb(b[j ++]);

      for(int i = c.size() - 2; i >= 0; i --)
            c[i].sc = max(c[i].sc, c[i + 1].sc);
}

void build(int v = 1, int tl = 1, int tr = n)
{
      if(tl == tr)
            t[v].pb(mk(c[tl], b[tl]));
      else
      {
            int tm = (tl + tr) >> 1;
            build(v << 1, tl, tm);
            build((v << 1) |  1, tm + 1, tr);
            Merge(t[v << 1], t[(v << 1) | 1], t[v]);
      }
}

int get(int pos, int v = 1, int tl = 1, int tr = n)
{
      if(tr < pos) return 0;

      if(pos <= tl)
      {
            if(t[v].back().fr - s2 < 0) return 0;
            int lo = 0, hi = t[v].size() - 1;

            while(hi - lo > 1)
            {
                  int md = (lo + hi) >> 1;
                  if(t[v][md].fr - s2 >= 0)
                        hi = md;
                  else
                        lo = md;
            }

            if(t[v][lo].fr - s2 >= 0) hi = lo;

            return t[v][hi].sc;
      }

      int tm = (tl + tr) >> 1;

      if(pos <= tm)
            return get(pos, v << 1, tl, tm);
      return get(pos, (v << 1) | 1, tm + 1, tr);
}

int main()
{
      cin >> n;

      for(int i = 1; i <= n; i ++)
      {
            cin >> a[i] >> b[i] >> c[i];
            cb[i] = b[i];
            cc[i] = c[i];
            b[i] += b[i - 1];
            c[i] += c[i - 1];
      }

      for(int i = 1; i <= n; i ++)
            c[i] -= a[i];

      build();

      for(int i = 1; i <= n; i ++)
      {
            ans = max(ans, get(i) - s1);
            for(int j = i; j <= n; j ++)
            {
                  ll res = b[j] - s1, sum = c[j] - s2;
                  if(sum + a[i] < 0) continue;
                  ans = max(ans, res);
            }
            s1 += cb[i];
            s2 += cc[i];
      }

      cout << ans << endl;
}

Compilation message (stderr)

divide.cpp: In function 'void Merge(std::vector<std::pair<int, int> >, std::vector<std::pair<int, int> >, std::vector<std::pair<int, int> >&)':
divide.cpp:22:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       while(i < a.size() && j < b.size())
               ^
divide.cpp:22:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       while(i < a.size() && j < b.size())
                               ^
divide.cpp:28:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       while(i < a.size())
               ^
divide.cpp:30:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
       while(j < b.size())
               ^

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 0 / 52