Submission #1690943

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Source Code Expand

#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define IOS ios::sync_with_stdio(false); cin.tie(0);
#define sd(n) scanf("%d",&n)
#define sl(n) scanf("%lld",&n)
#define pd(n) printf("%d",n)
#define pl(n) printf("%lld",n)
#define sf(n) scanf("%Lf",&n)
#define pf(n) printf("%.12Lf",n)
#define psp printf(" ")
#define endc printf("\n")

using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;

const int maxn = 4e4 + 600;
const ld  eps  = 1e-13;
const ld LIM = 3e8;

ld a[maxn];
ld b[maxn];
ld c[maxn];
int occ[maxn];
int n; ld sep;
int bit[maxn];


bool sepsort(int i,int j) {
	return ((c[i] - a[i]*sep)/b[i]) < ((c[j] - a[j]*sep)/b[j]);
}

vector<int> getseq(ld z) {
	sep = z;
	vector<int> ans; for (int i = 1; i <= n; i++) ans.pb(i);
	sort(ans.begin(), ans.end(), sepsort);

	return ans;
}

void upd(int x) {
	while (x < maxn) { bit[x]++; x += x & (-x); }
}

int qry(int x) {
	int ans = 0;
	while (x > 0) { ans += bit[x]; x -= x & (-x); }
	return ans;
}

int inv(vector<int> A) {
	for (int i = 0; i < n; i++) A[i] = occ[A[i]];
	fill(bit, bit + maxn, 0);

	int ans = 0;

	for (int i = n - 1 ; i >= 0; i--) {
		ans += qry(A[i]); upd(A[i]);
	}

	return ans;
}

ld solve() {
	int C = (n * (n - 1)/2)/2;
	vector<int> S = getseq(LIM), Q;
	
	for (int i = 0; i < n; i++) occ[S[i]] = i + 1;

	ld l = -LIM, r = LIM;
	while (r - l > eps) {
		ld mid = (l + r)/2;
		Q = getseq(mid);
		int z = inv(Q);
		if (z > C) l = mid;
		else r = mid;
	}

	return (l + r)/2;
}

int main() {
	sd(n);
	for (int i = 1; i <= n; i++) {
		sf(a[i]); sf(b[i]); sf(c[i]);
	}
	
	ld mx = solve();
	for (int i = 1; i <= n; i++) swap(a[i], b[i]);
	ld my = solve();

	cout<<setprecision(12)<<mx<<" "<<my<<endl;	

	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:85:7: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  sd(n);
       ^
./Main.cpp:87:11: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   sf(a[i]); sf(b[i]); sf(c[i]);
           ^
./Main.cpp:87:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   sf(a[i]); sf(b[i]); sf(c[i]);
                     ^
./Main.cpp:87:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   sf(a[i]); sf(b[i]); sf(c[i]);
                               ^

Judge Result