Submission #1000924

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Source Code Expand

#include <string>
#include <vector>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <queue>
#include <map>
#include <set>
#include <iostream>
#include <sstream>
#include <cstring>
#include <numeric>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define F0(i,n) for (int i = 0; i < n; i++)
#define F1(i,n) for (int i = 1; i <= n; i++)
#define CL(a,x) memset(x, a, sizeof(x));
#define SZ(x) ((int)x.size())
const double eps = 1e-10;
const int inf = 1000000009;
int i, j, k, m, n, l;
int ans;
int x[15], y[15], a[15];
double d[15][15], e[15], dp[15][1<<15];

int ok(double R) {
	F0(i, n) e[i] = a[i] - R;

	F0(i, n) F0(j, (1 << n)) dp[i][j] = -1e100;
	F0(i, n) dp[i][(1 << i)] = e[i];

	F0(mask, (1 << n)) F0(i, n) if ((1 << i)&mask) {
		F0(j, n) if (((1 << j)&mask) == 0) {
			int mm = mask | (1 << j);

			if (dp[i][mask] >= 0) {
				dp[j][mm] = max(dp[j][mm], e[j]);
			}

			//if (e[i] < 0 && e[j] < 0) continue;
			//if (e[i] >= 0 && e[j] >= 0) continue;

			double total = dp[i][mask] + e[j] - d[i][j];

			dp[i][mm] = max(dp[i][mm], total);
			dp[j][mm] = max(dp[j][mm], total);
		}
	}
	F0(i, n) if (dp[i][(1 << n) - 1] >= 0) return 1;
	return 0;
}

int main() {
	//freopen("x.in", "r", stdin);

	cin >> n;
	F0(i, n) {
		cin >> x[i] >> y[i] >> a[i];
	}

	F0(i, n) F0(j, n) d[i][j] = hypot(1.0*x[i] - x[j], 1.0*y[i] - y[j]);

	double P = 1e100, Q = 0, R;
	F0(i, n) Q = max(Q, 1.0 * a[i]);
	F0(i, n) P = min(P, 1.0 * a[i]);
	F0(it, 60) {
		R = (P + Q) / 2;
		if (ok(R)) P = R; else Q = R;
	}
	printf("%.10lf\n", P);
	return 0;
}

Submission Info

Judge Result