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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#498759 | #7674. Skiing | Max_s_xaM | WA | 1ms | 6768kb | C++14 | 7.0kb | 2024-07-30 19:26:27 | 2024-07-30 19:26:27 |
Judging History
answer
#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
typedef long long ll;
typedef double lf;
// #define DEBUG 1
struct IO
{
#define MAXSIZE (1 << 20)
#define isdigit(x) (x >= '0' && x <= '9')
char buf[MAXSIZE], *p1, *p2;
char pbuf[MAXSIZE], *pp;
#if DEBUG
#else
IO() : p1(buf), p2(buf), pp(pbuf) {}
~IO() {fwrite(pbuf, 1, pp - pbuf, stdout);}
#endif
#define gc() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, MAXSIZE, stdin), p1 == p2) ? ' ' : *p1++)
#define blank(x) (x == ' ' || x == '\n' || x == '\r' || x == '\t')
template <typename T>
void Read(T &x)
{
#if DEBUG
std::cin >> x;
#else
bool sign = 0; char ch = gc(); x = 0;
for (; !isdigit(ch); ch = gc())
if (ch == '-') sign = 1;
for (; isdigit(ch); ch = gc()) x = x * 10 + (ch ^ 48);
if (sign) x = -x;
#endif
}
void Read(char *s)
{
#if DEBUG
std::cin >> s;
#else
char ch = gc();
for (; blank(ch); ch = gc());
for (; !blank(ch); ch = gc()) *s++ = ch;
*s = 0;
#endif
}
void Read(char &c) {for (c = gc(); blank(c); c = gc());}
void Push(const char &c)
{
#if DEBUG
putchar(c);
#else
if (pp - pbuf == MAXSIZE) fwrite(pbuf, 1, MAXSIZE, stdout), pp = pbuf;
*pp++ = c;
#endif
}
template <typename T>
void Write(T x)
{
if (x < 0) x = -x, Push('-');
static T sta[35];
int top = 0;
do sta[top++] = x % 10, x /= 10; while (x);
while (top) Push(sta[--top] ^ 48);
}
template <typename T>
void Write(T x, char lst) {Write(x), Push(lst);}
} IO;
#define Read(x) IO.Read(x)
#define Write(x, y) IO.Write(x, y)
#define Put(x) IO.Push(x)
using namespace std;
const int MAXN = 260;
const lf eps = 1e-9;
int n; lf vy, ax;
struct Point
{
lf x, y; int id;
bool operator < (const Point &u) const { return (fabs(y - u.y) < eps ? id < u.id : y < u.y); }
}a[MAXN];
struct Line
{
lf x, y;
bool operator < (const Line &u) const { return x == u.x ? y > u.y : x < u.x; }
};
struct Answer
{
// vector <int> res;
vector <Line> d;
}f[MAXN][MAXN];
vector <Line> mg;
inline lf Calc(lf v1, lf v2, lf t)
{
return (v1 + v2) * t / 2;
}
inline pair <lf, lf> Solve(lf mn, lf mx, lf t, lf dist)
{
if (fabs(t) < eps) return {mn, mx};
lf l = dist / t - ax * t / 2, r = dist / t + ax * t / 2, b, c, delta;
if (Calc(mx + ax * t, mx, t) < dist) return {1e20, -1e20};
if (Calc(mx - ax * t, mx, t) < dist)
{
b = -2 * (ax * t + mx), c = -ax * ax * t * t - 2 * ax * t * mx + mx * mx + 4 * ax * dist;
delta = b * b - 4 * c;
l = max(l, (-b - sqrt(delta)) / 2);
}
if (Calc(mn - ax * t, mn, t) > dist) return {1e20, -1e20};
if (Calc(mn + ax * t, mn, t) > dist)
{
b = 2 * (ax * t - mn), c = -ax * ax * t * t + 2 * ax * t * mn + mn * mn - 4 * ax * dist;
delta = b * b - 4 * c;
r = min(r, (-b + sqrt(delta)) / 2);
}
return make_pair(l, r);
}
int main()
{
// freopen("A.in", "r", stdin);
// freopen("A.out", "w", stdout);
#if DEBUG
#else
ios::sync_with_stdio(0), cin.tie(0);
#endif
Read(n), Read(vy), Read(ax);
for (int i = 1, j = 1; i <= n; i++, j++)
{
Read(a[i].x), Read(a[i].y);
if (a[i].y < 0) { i--, n--; continue; }
a[i].y /= vy, a[i].id = j;
}
a[++n] = Point{0, 0, 0};
sort(a + 1, a + n + 1);
if (ax == 0)
{
bool flag = 0;
for (int i = 2; i <= n; i++)
if (a[i].x == 0) { cout << a[i].id << ' '; flag = 1; }
if (!flag) cout << "Cannot visit any targets\n";
return 0;
}
// for (int i = 1; i <= n; i++) cout << a[i].x << ' ' << a[i].y << '\n';
for (int i = 1; i <= n; i++)
{
// f[i][1].res.push_back(a[i].id);
f[i][1].d.push_back(Line{-1e50, 1e50});
}
for (int i = n; i >= 1; i--)
for (int k = 1; k <= n - i + 1; k++)
{
if (!f[i][k].d.size()) continue;
sort(f[i][k].d.begin(), f[i][k].d.end());
lf pl = -1e51, pr = -1e51;
mg.clear();
for (auto [x, y] : f[i][k].d)
{
if (x > pr)
{
if (pl != -1e51) mg.push_back(Line{pl, pr});
pl = x, pr = y;
}
else pr = max(pr, y);
}
if (pl != -1e51) mg.push_back(Line{pl, pr});
f[i][k].d = mg;
// cout << "Solve " << a[i].id << ' ' << k << ' ' << a[i].x << ' ' << a[i].y << "\n";
// for (auto [x, y] : f[i][k].d) cout << x << ' ' << y << "\n";
// cout << "\n";
for (int j = i - 1; j >= 1; j--)
{
// if (f[j].res.size() > f[i].res.size() + 1 || (f[j].res.size() == f[i].res.size() + 1 && f[j].res[1] < a[i].id)) continue;
lf len = a[i].y - a[j].y, dist = a[i].x - a[j].x;
mg.clear();
for (auto [x, y] : f[i][k].d)
{
auto cur = Solve(x, y, len, dist);
if (cur.first > cur.second) continue;
mg.push_back(Line{cur.first, cur.second});
}
if (mg.size())
{
if (j == 1)
{
bool flag = 0;
for (auto [x, y] : mg)
if ((x < 0 || fabs(x) < eps) && (y > 0 || fabs(y) < eps)) { flag = 1; break; }
if (!flag) continue;
}
// f[j].res = {a[j].id};
// for (auto x : f[i].res) f[j].res.push_back(x);
for (auto x : mg) f[j][k + 1].d.push_back(x);
// cout << "Trans " << a[i].id << ' ' << k << ' ' << a[j].id << '\n';
}
}
}
int x = 1, y = 1;
while (f[1][y].d.size()) y++; y--;
if (y == 1) return cout << "Cannot visit any targets\n", 0;
// cout << "-----------\n";
// cout << x << ' ' << y << "\n";
lf l = 0, r = 0; a[n + 1].id = 2e9;
for (int i = y - 1; i >= 1; i--)
{
int p = n + 1; lf pl = 0, pr = 0;
// cout << "srch " << x << ' ' << y << '\n';
for (int j = x + 1; j <= n; j++)
{
if (a[j].id > a[p].id || !f[j][i].d.size()) continue;
lf len = a[j].y - a[x].y, dist = a[j].x - a[x].x;
auto cur = Solve(l, r, len, dist);
if (cur.first > cur.second) continue;
for (auto [xx, yy] : f[j][i].d)
if (xx <= cur.second && cur.first <= yy) { pl = cur.first, pr = cur.second, p = j; break; }
}
x = p, l = pl, r = pr;
cout << a[x].id << ' ';
}
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 1ms
memory: 6540kb
input:
4 100 400 -100 100 50 200 -100 300 150 300
output:
1 2 4
result:
ok single line: '1 2 4 '
Test #2:
score: 0
Accepted
time: 1ms
memory: 6768kb
input:
1 100 100 1000 10
output:
Cannot visit any targets
result:
ok single line: 'Cannot visit any targets'
Test #3:
score: 0
Accepted
time: 1ms
memory: 5928kb
input:
0 100 100
output:
Cannot visit any targets
result:
ok single line: 'Cannot visit any targets'
Test #4:
score: 0
Accepted
time: 1ms
memory: 5192kb
input:
2 100 100 100 100 -100 100
output:
Cannot visit any targets
result:
ok single line: 'Cannot visit any targets'
Test #5:
score: -100
Wrong Answer
time: 0ms
memory: 5248kb
input:
2 1000 2001 1000 1000 -1000 1000
output:
1 2
result:
wrong answer 1st lines differ - expected: '1', found: '1 2 '