Submission #1000976
Source Code Expand
#include <bits/stdc++.h>
#include <assert.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define PB push_back
#define MP make_pair
#define MOD 1000000007LL
#define endl "\n"
const ll UNDEF = -1;
const ll INF=1e18;
template<typename T> inline bool chkmax(T &aa, T bb) { return aa < bb ? aa = bb, true : false; }
template<typename T> inline bool chkmin(T &aa, T bb) { return aa > bb ? aa = bb, true : false; }
typedef pair<ll,ll> pll;
#ifdef DEBUG
#define debug(args...) {dbg,args; cerr<<endl;}
#else
#define debug(args...) // Just strip off all debug tokens
#endif
struct debugger
{
template<typename T> debugger& operator , (const T& v)
{
cerr<<v<<" ";
return *this;
}
} dbg;
// Two-phase simplex algorithm for solving linear programs of the form
//
// maximize c^T x
// subject to Ax <= b
// x >= 0
//
// INPUT: A -- an m x n matrix
// b -- an m-dimensional vector
// c -- an n-dimensional vector
// x -- a vector where the optimal solution will be stored
//
// OUTPUT: value of the optimal solution (infinity if unbounded
// above, nan if infeasible)
//
// To use this code, create an LPSolver object with A, b, and c as
// arguments. Then, call Solve(x).
typedef ld DOUBLE;
typedef vector<DOUBLE> VD;
typedef vector<VD> VVD;
typedef vector<int> VI;
const DOUBLE EPS = 1e-12;
struct LPSolver {
int m, n;
VI B, N;
VVD D;
LPSolver(const VVD &A, const VD &b, const VD &c) :
m(b.size()), n(c.size()), N(n + 1), B(m), D(m + 2, VD(n + 2)) {
for (int i = 0; i < m; i++) for (int j = 0; j < n; j++) D[i][j] = A[i][j];
for (int i = 0; i < m; i++) { B[i] = n + i; D[i][n] = -1; D[i][n + 1] = b[i]; }
for (int j = 0; j < n; j++) { N[j] = j; D[m][j] = -c[j]; }
N[n] = -1; D[m + 1][n] = 1;
}
void Pivot(int r, int s) {
for (int i = 0; i < m + 2; i++) if (i != r)
for (int j = 0; j < n + 2; j++) if (j != s)
D[i][j] -= D[r][j] * D[i][s] / D[r][s];
for (int j = 0; j < n + 2; j++) if (j != s) D[r][j] /= D[r][s];
for (int i = 0; i < m + 2; i++) if (i != r) D[i][s] /= -D[r][s];
D[r][s] = 1.0 / D[r][s];
swap(B[r], N[s]);
}
bool Simplex(int phase) {
int x = phase == 1 ? m + 1 : m;
while (true) {
int s = -1;
for (int j = 0; j <= n; j++) {
if (phase == 2 && N[j] == -1) continue;
if (s == -1 || D[x][j] < D[x][s] || D[x][j] == D[x][s] && N[j] < N[s]) s = j;
}
if (D[x][s] > -EPS) return true;
int r = -1;
for (int i = 0; i < m; i++) {
if (D[i][s] < EPS) continue;
if (r == -1 || D[i][n + 1] / D[i][s] < D[r][n + 1] / D[r][s] ||
(D[i][n + 1] / D[i][s]) == (D[r][n + 1] / D[r][s]) && B[i] < B[r]) r = i;
}
if (r == -1) return false;
Pivot(r, s);
}
}
DOUBLE Solve(VD &x) {
int r = 0;
for (int i = 1; i < m; i++) if (D[i][n + 1] < D[r][n + 1]) r = i;
if (D[r][n + 1] < -EPS) {
Pivot(r, n);
if (!Simplex(1) || D[m + 1][n + 1] < -EPS) return -numeric_limits<DOUBLE>::infinity();
for (int i = 0; i < m; i++) if (B[i] == -1) {
int s = -1;
for (int j = 0; j <= n; j++)
if (s == -1 || D[i][j] < D[i][s] || D[i][j] == D[i][s] && N[j] < N[s]) s = j;
Pivot(i, s);
}
}
if (!Simplex(2)) return numeric_limits<DOUBLE>::infinity();
x = VD(n);
for (int i = 0; i < m; i++) if (B[i] < n) x[B[i]] = D[i][n + 1];
return D[m][n + 1];
}
};
typedef pll point;
long long ccw(point a, point b, point c) {
b.first -= a.first; b.second -= a.second;
c.first -= a.first; c.second -= a.second;
return b.first * (long long)c.second - c.first * (long long)b.second;
}
#define fst first
#define snd second
pair<ld,pair<ld,ld> > getform(pll p, pll q) {
ll px=p.fst,py=p.snd;
ll qx=q.fst,qy=q.snd;
ld a=py-qy;
ld b=qx-px;
ld c=px*qy-qx*py;
return MP(a,MP(b,c));
}
pll vp[3];
ld go(ld t) {
ld ct=cos(t);
ld st=sin(t);
VVD A;
VD B;
A.resize(6);
B.resize(6);
for (ll k=0;k<2;k++) {
for (ll id=0;id<3;id++) {
pair<ld,pair<ld,ld> > line = getform(vp[(id+1)%3],vp[id]);
ld a=line.first,b=line.snd.fst,c=line.snd.snd;
ld norm=sqrt(a*a+b*b);
ll i=k*3+id;
A[i].resize(3);
A[i][0]=-a/norm;
A[i][1]=-b/norm;
A[i][2]=1;
if (k) {
A[i][2]=1-(2*(a*ct-b*st)/norm);
}
B[i]=c/norm;
}
}
VD C; C.resize(3);
C[2]=1;
VD x;
LPSolver solver(A, B, C);
ld value = solver.Solve(x);
return value;
}
const ll NUM=6000;
int main()
{
ios_base::sync_with_stdio(false); cin.tie(0);
cout<<fixed<<setprecision(10);
for (ll i=0;i<3;i++) {
ll x,y; scanf("%lld%lld",&x,&y); vp[i]=MP(x,y);
}
if (ccw(vp[0],vp[1],vp[2])>0) reverse(vp,vp+3);
assert(ccw(vp[0],vp[1],vp[2])<0);
ld final=0;
ld tick=M_PI/NUM;
for (ll i=0;i<NUM;i++) {
ld imin=tick*i,imax=tick*(i+1);
for (ll j=0;j<40;j++) {
ld imid=(imin+imax)/2;
ld g0=go(imid),g1=go(imid+1e-11);
chkmax(final,max(g0,g1));
if (g0<g1) {
imin=imid;
}
else imax=imid;
}
}
cout<<final<<endl;
}
Submission Info
Submission Time
2016-11-28 13:52:55+0900
Task
B - Inscribed Bicycle
User
LiChenKoh
Language
C++14 (GCC 5.4.1)
Score
500
Code Size
5681 Byte
Status
AC
Exec Time
1335 ms
Memory
512 KB
Compile Error
./Main.cpp: In function ‘int main()’:
./Main.cpp:170:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
ll x,y; scanf("%lld%lld",&x,&y); vp[i]=MP(x,y);
^
Judge Result
Set Name
Sample
All
Score / Max Score
0 / 0
500 / 500
Status
Set Name
Test Cases
Sample
example0.txt, example1.txt
All
000.txt, 001.txt, 002.txt, 003.txt, 004.txt, 005.txt, 006.txt, 007.txt, 008.txt, 009.txt, 010.txt, 011.txt, 012.txt, 013.txt, 014.txt, 015.txt, example0.txt, example1.txt
Case Name
Status
Exec Time
Memory
000.txt
AC
1154 ms
512 KB
001.txt
AC
1268 ms
256 KB
002.txt
AC
1236 ms
256 KB
003.txt
AC
1221 ms
256 KB
004.txt
AC
1247 ms
256 KB
005.txt
AC
1246 ms
256 KB
006.txt
AC
1252 ms
256 KB
007.txt
AC
1230 ms
256 KB
008.txt
AC
1208 ms
256 KB
009.txt
AC
1246 ms
256 KB
010.txt
AC
1335 ms
256 KB
011.txt
AC
1220 ms
256 KB
012.txt
AC
1221 ms
256 KB
013.txt
AC
1236 ms
256 KB
014.txt
AC
1214 ms
256 KB
015.txt
AC
1262 ms
256 KB
example0.txt
AC
1123 ms
256 KB
example1.txt
AC
1241 ms
256 KB