結果
| 問題 |
No.1122 Plane Tickets
|
| コンテスト | |
| ユーザー |
startcpp
|
| 提出日時 | 2020-07-22 22:53:33 |
| 言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 3 ms / 1,000 ms |
| コード長 | 3,375 bytes |
| コンパイル時間 | 1,215 ms |
| コンパイル使用メモリ | 82,316 KB |
| 実行使用メモリ | 6,944 KB |
| 最終ジャッジ日時 | 2024-06-23 17:35:58 |
| 合計ジャッジ時間 | 2,280 ms |
|
ジャッジサーバーID (参考情報) |
judge2 / judge4 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 2 |
| other | AC * 55 |
ソースコード
//http://www.prefield.com/algorithm/math/two_stage_simplex.html
#include <iostream>
#include <cstdio>
#include <cmath>
#include <vector>
using namespace std;
typedef vector<double> Array;
typedef vector<Array> Matrix;
const double EPS = 1e-8;
enum { OPTIMAL, UNBOUNDED, NOSOLUTION, UNKNOWN };
struct two_stage_simplex {
int N, M, st;
Matrix a;
vector<int> s;
two_stage_simplex(const Matrix &A, const Array &b, const Array &c)
: N(A.size()), M(A[0].size()), a(N+2, Array(M+N+1)), s(N+2), st(UNKNOWN) {
for (int j = 0; j < M; ++j) a[N+1][j] = c[j]; // make simplex table
for (int i = 0; i < N; ++i)
for (int j = 0; j < M; ++j) a[i+1][j] = A[i][j];
for (int i = 0; i < N; ++i) a[i+1][M+N] = b[i]; // add helper table
for (int i = 0; i < N; ++i) a[ 0 ][i+M] = 1;
for (int i = 0; i < N; ++i) a[i+1][i+M] = 1;
for (int i = 0; i < N; ++i) s[i+1] = i+M;
for (int i = 1; i <= N; ++i)
for (int j = 0; j <= N+M; ++j) a[0][j] += a[i][j];
st = solve();
}
int status() const { return st; }
double solution() const { return -a[0][M]; }
double solution(Array &x) const {
x.resize(M, 0);
for (int i = 0; i < N; ++i)
x[s[i+1]] = a[i+1].back();
return -a[0][M];
}
int solve() {
M += N; N += 1;
solve_sub(); // solve stage one
if (solution() > EPS) return NOSOLUTION;
N -= 1; M -= N;
swap(a[0], a.back()); a.pop_back(); // modify table
for (int i = 0; i <= N; ++i) {
swap(a[i][M], a[i].back());
a[i].resize(M+1);
}
return solve_sub(); // solve stage two
}
int solve_sub() {
int p, q;
while (1) {
//print();
for (q = 0; q <= M && a[0][q] >= -EPS; ++q);
for (p = 0; p <= N && a[p][q] <= EPS; ++p);
if (q >= M || p > N) break;
for (int i = p+1; i <= N; ++i) // bland's care for cyclation
if (a[i][q] > EPS)
if (a[i][M]/a[i][q] < a[p][M]/a[p][q] ||
(a[i][M]/a[i][q] == a[p][M]/a[p][q] && s[i] < s[q])) p = i;
pivot(p, q);
}
if (q >= M) return OPTIMAL;
else return UNBOUNDED;
}
void pivot(int p, int q) {
for (int j = 0; j <= N; ++j)
for (int k = M; k >= 0; --k)
if (j != p && k != q)
a[j][k] -= a[p][k]*a[j][q]/a[p][q];
for (int j = 0; j <= N; ++j)
if (j != p) a[j][q] = 0;
for (int k = 0; k <= M; ++k)
if (k != q) a[p][k] = a[p][k]/a[p][q];
a[p][q] = 1.0;
s[p] = q;
}
};
int main() {
/*for (int n, m; cin >> n >> m; ) {
Array c(n+m), b(m);
for (int i = 0; i < n; ++i)
cin >> c[i], c[i] *= -1;
Matrix A(m, Array(n+m));
for (int i = 0; i < m; ++i) {
for (int j = 0; j < n; ++j)
cin >> A[i][j];
A[i][n+i] = 1;
cin >> b[i];
}
two_stage_simplex tss(A, b, c);
double ans = -tss.solution();
printf("Nasa can spend %.0f taka.\n", ans + 0.5 - EPS);
}*/
//整数計画ソルバーが欲しい(これは実数で計画しているからWAだと思う)
Array c(5), b(5);
for (int i = 0; i < 5; i++) { c[i] = 1; c[i] *= -1; }
Matrix A(5, Array(10));
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 3; j++) {
A[i][(i + j) % 5] = 1;
}
A[i][5 + i] = 1;
}
cin >> b[2] >> b[3] >> b[4] >> b[0] >> b[1];
two_stage_simplex tss(A, b, c);
double ans = -tss.solution();
printf("%lld\n", (long long)(ans + 1e-9));
return 0;
}
startcpp