HDU 5017 Ellipsoid(西安网络赛K题)
2014-09-15 16:30
295 查看
HDU 5017 Ellipsoid
题目链接思路:模拟退火大法好!
代码:
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;
const int D[8][2] = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}, {1, 1}, {-1, -1}, {1, -1}, {-1, 1}};
double a, b, c, d, e, f;
const double INF = 1e9;
const double eps = 1e-8;
double dis(double x, double y, double z) {
return sqrt(x * x + y * y + z * z);
}
double cal(double x, double y) {
double A = c;
double B = d * y + e * x;
double C = f * x * y + a * x * x + b * y * y - 1;
double del = B * B - 4 * A * C;
if (del < 0) return 1e10;
del = sqrt(del);
double z1 = (-B + del) / A / 2;
double z2 = (-B - del) / A / 2;
if (dis(x, y, z1) < dis(x, y, z2)) return z1;
return z2;
}
double solve() {
double x = 0, y = 0, z = sqrt(1.0 / c);
double step = 1.0, r = 0.99;
while (step > eps) {
for (int i = 0; i < 8; i++) {
double xx = x + step * D[i][0];
double yy = y + step * D[i][1];
double zz = cal(xx, yy);
if (zz > INF) continue;
if (dis(xx, yy, zz) < dis(x, y, z)) {
x = xx; y = yy; z = zz;
}
}
step *= r;
}
return dis(x, y, z);
}
int main() {
while (~scanf("%lf%lf%lf%lf%lf%lf", &a, &b, &c, &d, &e, &f)) {
printf("%.7lf\n", solve());
}
return 0;
}
相关文章推荐
- hdu 5017 Ellipsoid(西安网络赛 1011)
- hdu 5017 Ellipsoid(西安网络赛 1011)
- hdu 5017 Ellipsoid 模拟退火算法 西安网络赛
- HDU 5011 Game(西安网络赛E题)
- HDU 5014 Number Sequence(西安网络赛H题)
- 西安网络赛三道水题 HDU 5007 HDU 5011 HDU 5015
- hdu 5015 233 Matrix 2014年西安网络赛I题
- HDU 5007 Post Robot(西安网络赛A题)
- hdu 5014(贪心+异或 西安网络赛)
- hdu 5014 Number Sequence 西安网络赛
- HDU 5017 Ellipsoid(模拟退火算法)
- HDU 5007 Post Robot KMP (ICPC西安赛区网络预选赛 1001)
- hdu 5012(广搜,西安网络赛)
- hdu 5011 Game(2014 西安网络赛)
- HDU 5009 Paint Pearls(西安网络赛C题) dp+离散化+优化
- hdu 2014西安赛区网络赛 5011Game
- HDU 5012 Dice(西安网络赛F题)
- hdu 5017 Ellipsoid(三分)
- hdu 5015 233 Matrix(西安网络赛 1009)
- HDU 5017 Ellipsoid(模拟退火)