Submission #1004501

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004501		jamjanek	Bulldozer (JOI17_bulldozer)	C++14	75 / 100	1836 ms	33472 KiB

bulldozer

   #include<bits/stdc++.h>
    using namespace std;
    pair<pair<int,int>,int>tab[2010];
    int miejsce[2010];
    vector<pair<int,int>>vec;
int sign(long long x){
  if(x<0)return -1;
  return x>0;
}
bool notparallel(pair<int,int> a, pair<int,int> b){
  long long Ax=tab[a.first].first.first-tab[a.second].first.first, Ay=tab[a.first].first.second-tab[a.second].first.second, Bx=tab[b.first].first.first-tab[b.second].first.first, By=tab[b.first].first.second-tab[b.second].first.second;
  if(sign(Ax)!=sign(Bx) || sign(Ay)!=sign(By))return 1;
  return Ax*By!=Ay*Bx;
}
bool cmp(pair<int,int>a, pair<int,int>b){
  long long Ax=tab[a.first].first.first-tab[a.second].first.first, Ay=tab[a.first].first.second-tab[a.second].first.second, Bx=tab[b.first].first.first-tab[b.second].first.first, By=tab[b.first].first.second-tab[b.second].first.second;
  if(!notparallel(a,b))return 0;
  if(Bx==0&&By>0)return 0;
  if(Ax==0&&Ay>0)return 1;
  if(Bx==0)return Ax>0;
  if(Ax==0)return Bx<0;
  if(sign(Ax)!=sign(Bx))return Ax>0;
  return Ay*Bx>By*Ax;//Ay/Ax>By/Bx;
}
const int base=1<<11;
struct node{long long sum, maxi, lmaxi, rmaxi;};
node tree[2*base];
void ustaw(int x, long long val){
  x+=base;
  tree[x].sum=val;
  tree[x].lmaxi = tree[x].rmaxi = tree[x].maxi=max(0ll,val);
  x/=2;
  while(x>0){
    tree[x].maxi=max({tree[x*2].maxi, tree[x*2+1].maxi, tree[x*2].rmaxi+tree[x*2+1].lmaxi});
    tree[x].sum=tree[x*2].sum+tree[x*2+1].sum;
    tree[x].lmaxi=max(tree[x*2].lmaxi, tree[x*2].sum+tree[x*2+1].lmaxi);
    tree[x].rmaxi=max(tree[x*2+1].rmaxi, tree[x*2+1].sum+tree[x*2].rmaxi);
    x/=2;
  }
}
    int main()
    {
      int n, i, j;
      scanf("%d", &n);
      for(i=0;i<n;i++){
        scanf("%d%d%d", &tab[i].first.first, &tab[i].first.second, &tab[i].second);
      }
      sort(tab, tab+n);
      for(i=0;i<n;i++){
        for(j=0;j<n;j++)
          if(i!=j){
            vec.push_back({i,j});
          }
      }
      sort(vec.begin(), vec.end(), cmp);
      for(i=0;i<n;i++){
        ustaw(i, tab[i].second);
        miejsce[i] = i;
      }
        long long res = max(0ll, tree[1].maxi);
      for(i=0;i<(int)vec.size();i++){
        swap(miejsce[vec[i].first], miejsce[vec[i].second]);
        ustaw(miejsce[vec[i].first], tab[vec[i].first].second);
        ustaw(miejsce[vec[i].second], tab[vec[i].second].second);
        if(i!=(int)vec.size()-1 && notparallel(vec[i], vec[i+1]))
          res = max(res, tree[1].maxi);
      }
      printf("%lld\n", res);
    }

Compilation message (stderr)

bulldozer.cpp: In function 'int main()':
bulldozer.cpp:44:12: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |       scanf("%d", &n);
      |       ~~~~~^~~~~~~~~~
bulldozer.cpp:46:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |         scanf("%d%d%d", &tab[i].first.first, &tab[i].first.second, &tab[i].second);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 20 / 20
• Subtask 3: 35 / 35
• Subtask 4: 20 / 20
• Subtask 5: 0 / 20