Submission #72436

#	Time	Username	Problem	Language	Result	Execution time	Memory
72436		이시대의진정한갓겜스타투 (#118)	Hill Reconstruction (FXCUP3_hill)	C++17	100 / 100	989 ms	11200 KiB

hill

#include<bits/stdc++.h>
using namespace std;

#define VA_NUM_ARGS(...) VA_NUM_ARGS_IMPL_((0,__VA_ARGS__, 6,5,4,3,2,1))
#define VA_NUM_ARGS_IMPL_(tuple) VA_NUM_ARGS_IMPL tuple
#define VA_NUM_ARGS_IMPL(_0,_1,_2,_3,_4,_5,_6,N,...) N
#define macro_dispatcher(macro, ...) macro_dispatcher_(macro, VA_NUM_ARGS(__VA_ARGS__))
#define macro_dispatcher_(macro, nargs) macro_dispatcher__(macro, nargs)
#define macro_dispatcher__(macro, nargs) macro_dispatcher___(macro, nargs)
#define macro_dispatcher___(macro, nargs) macro ## nargs
#define Debug1(a)           cout<<#a<<"="<<(a)<<"\n"
#define Debug2(a,b)         cout<<#a<<"="<<(a)<<", "<<#b<<"="<<(b)<<"\n"
#define Debug3(a,b,c)       cout<<#a<<"="<<(a)<<", "<<#b<<"="<<(b)<<", "<<#c<<"="<<(c)<<"\n"
#define Debug4(a,b,c,d)     cout<<#a<<"="<<(a)<<", "<<#b<<"="<<(b)<<", "<<#c<<"="<<(c)<<", "<<#d<<"="<<(d)<<"\n"
#define Debug5(a,b,c,d,e)   cout<<#a<<"="<<(a)<<", "<<#b<<"="<<(b)<<", "<<#c<<"="<<(c)<<", "<<#d<<"="<<(d)<<", "<<#e<<"="<<(e)<<"\n"
#define Debug6(a,b,c,d,e,f) cout<<#a<<"="<<(a)<<", "<<#b<<"="<<(b)<<", "<<#c<<"="<<(c)<<", "<<#d<<"="<<(d)<<", "<<#e<<"="<<(e)<<", "<<#f<<"="<<(f)<<"\n"
#define Debug(...) macro_dispatcher(Debug, __VA_ARGS__)(__VA_ARGS__)
#define DA(a,n) cout<<#a<<"=["; printarray(a,n); cout<<"]\n"
#define DAR(a,n,s) cout<<#a<<"["<<s<<"-"<<n-1<<"]=["; printarray(a,n,s); cout<<"]\n"

#define TT1 template<class T>
#define TT1T2 template<class T1, class T2>
#define TT1T2T3 template<class T1, class T2, class T3>
template<class T, size_t N> ostream& operator << (ostream& os, const array<T, N>& v);
TT1T2 ostream& operator << (ostream& os, const pair<T1, T2>& p){ return os <<"("<<p.first<<", "<< p.second<<")"; }
TT1 ostream& operator << (ostream& os, const vector<T>& v){       bool f=1;os<<"[";for(auto& i : v) { if (!f)os << ", ";os<<i;f=0;}return os << "]"; }
template<class T, size_t N> ostream& operator << (ostream& os, const array<T, N>& v) {     bool f=1;os<<"[";for(auto& i : v) { if (!f)os << ", ";os<<i;f=0;}return os << "]"; }
TT1T2 ostream& operator << (ostream& os, const set<T1, T2>&v){    bool f=1;os<<"[";for(auto& i : v) { if (!f)os << ", ";os<<i;f=0;}return os << "]"; }
TT1T2 ostream& operator << (ostream& os, const multiset<T1,T2>&v){bool f=1;os<<"[";for(auto& i : v) { if (!f)os << ", ";os<<i;f=0;}return os << "]"; }
TT1T2T3 ostream& operator << (ostream& os, const map<T1,T2,T3>& v){ bool f = 1; os << "["; for (auto& ii : v) { if (!f)os << ", "; os << "(" << ii.first << " -> " << ii.second << ") "; f = 0; }return os << "]"; }
TT1T2 ostream& operator << (ostream& os, const multimap<T1, T2>& v){ bool f = 1; os << "["; for (auto& ii : v) { if (!f)os << ", "; os << "(" << ii.first << " -> " << ii.second << ") "; f = 0; }return os << "]"; }
TT1T2 ostream& operator << (ostream& os, priority_queue<T1, T2> v) { bool f = 1; os << "["; while (!v.empty()) { auto x = v.top(); v.pop(); if (!f) os << ", "; f = 0; os << x; } return os << "]"; }
TT1T2 void printarray(const T1& a, T2 sz, T2 beg = 0){ for (T2 i = beg; i<sz; i++) cout << a[i] << " "; cout << endl; }

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> Pi;
typedef pair<ll, ll> Pll;

#define Fi first
#define Se second
#define pb(x) push_back(x)
#define sz(x) (int)x.size()
#define rep(i, n) for(int i=0;i<n;i++)
#define repp(i, n) for(int i=1;i<=n;i++)
#define all(x) x.begin(), x.end()
#define geti1(X) cin >> X
#define geti2(X,Y) cin >> X >> Y
#define geti3(X,Y,Z) cin >> X >> Y >> Z
#define geti4(X,Y,Z,W) cin >> X >> Y >> Z >> W
#define GET_MACRO(_1,_2,_3,_4,NAME,...) NAME
#define geti(...) GET_MACRO(__VA_ARGS__, geti4, geti3, geti2, geti1) (__VA_ARGS__)

#define INF 987654321

#define endl '\n'
int N;ll C;
ll X[300500], Y[300500];
Pll p[300500]; bool die[300500];

Pll operator + (Pll a, Pll b){
	return {a.Fi+b.Fi, a.Se+b.Se};
}
Pll operator - (Pll a, Pll b){
	return {a.Fi-b.Fi, a.Se-b.Se};
}
ll operator * (Pll a, Pll b){
	return a.Fi*b.Fi + a.Se*b.Se;
}
ll operator / (Pll a, Pll b){
	return a.Fi*b.Se-a.Se*b.Fi;
}
ll area(Pll a, Pll b, Pll c){
	return abs((b-a)/(c-a));
}
ll area(int a, int b, int c){
	return area(p[a], p[b], p[c]  );
}

ll gcd(ll a, ll b){
	if( b == 0 ) return a;
	return gcd(b,a%b);
}
inline double slope(int a, int b){
	double dx = (double) (1.0*X[b]-1.0*X[a]);
	double dy = (double) (1.0*Y[b]-1.0*Y[a]);
	return dy/dx;
}
int prv[300500];
bool chk(double m){
	repp(i,N) if(i!=1) prv[i] = i-1;
	ll total = 0;
	for(int i=N;i>=2;i--) prv[i] = i-1;
	for(int i=N;i>=2;i--){
		if( slope(i-1,i) > m ){
			int j = i-2;
			prv[i-1] = 0;
			for(;j>=1;j--){
				ll tmp = (p[j+1]-p[j]) / (p[i]-p[j+1]);
				if( tmp < 0 ) total -= area(j,j+1,i);
				else total += area(j,j+1,i);
				prv[i] = j;
				if( tmp >= 0 && slope(j,i) <= m ) break;
				prv[j] = 0;
			}
			if( j == 0 ) return false;
			i = j+1;
			continue;
		}
	}
	return total <= C;
}

Pll ans = {0,1};
void setans(){
	Pll tmp = {1,0};
//	for(int i=1;i<=N;i++) printf("%d ",prv[i]);
//	printf("\n");
	for(int i=N;i>=2;i--) if(prv[i]!=0){
		int l = prv[i]; int r = i;
		ll dx = X[r] - X[l], dy = Y[r] - Y[l];
//		printf("%lld/%lld\n",dy,dx);
		if( tmp.Fi * dy > dx * tmp.Se ) tmp = {dx,dy};
	}
	ll g = gcd(tmp.Fi,tmp.Se);
	tmp.Fi /= g; tmp.Se /= g;

//	Debug(tmp,ans);
	if( tmp.Se * ans.Fi < ans.Se * tmp.Fi ) ans = tmp;
}

int main(){
	scanf("%d%lld",&N,&C); C *= 2;
	repp(i,N) scanf("%lld",X+i);
	repp(i,N) scanf("%lld",Y+i);
	repp(i,N) p[i] = {X[i],Y[i]};

	

	int bcnt = 200;
	double low = 0.0, high = 1e15;

	for(int i=2;i<=N;i++) prv[i] = i-1;
	setans();

//	double ans = -1.0;
	while( bcnt-- ){
		double mid = (low+high)/2.0;
		bool b = chk(mid);
		if( b ){
			setans();
			high = mid;
		}
		else{
			low = mid;
		}
	}


	printf("%lld/%lld",ans.Se,ans.Fi);

//	cout << setprecision(12) << ans << endl;
}

Compilation message (stderr)

hill.cpp: In function 'int main()':
hill.cpp:133:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%lld",&N,&C); C *= 2;
  ~~~~~^~~~~~~~~~~~~~~~
hill.cpp:134:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  repp(i,N) scanf("%lld",X+i);
            ~~~~~^~~~~~~~~~~~
hill.cpp:135:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  repp(i,N) scanf("%lld",Y+i);
            ~~~~~^~~~~~~~~~~~

• Subtask 1: 32 / 32
• Subtask 2: 68 / 68