| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1004499 | jamjanek | Bulldozer (JOI17_bulldozer) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#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(0,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);
}