QOJ.ac
QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #773047 | #8037. Gambler's Ruin | Andeviking | TL | 3ms | 3984kb | C++20 | 1.9kb | 2024-11-23 00:11:08 | 2024-11-23 00:11:09 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
vector<long double> p;
vector<ll> c;
int n;
const long double EPS = 1e-10L;
long double f(long double x, long double y)
{
ll sx = 0, sy = 0;
for (int i = 1; i <= n; ++i)
if (p[i] * x >= 1)
sx += c[i];
else if ((1 - p[i]) * y >= 1)
sy += c[i];
// cout << sx << ' ' << sy << ' ' << x << ' ' << y << ' ' << sx + sy - max(sx * x, sy * y) << '\n';
return sx + sy - max(sx * x, sy * y);
}
long double get(long double x)
{
long double l = 0, r = 1000000;
long double lans = f(x, l), rans = f(x, r);
long double ans = max(lans, rans);
for (int _ = 0; _ < 200; ++_) {
long double lmid = l + (r - l) / 3;
long double rmid = r - (r - l) / 3;
lans = f(x, lmid), rans = f(x, rmid);
ans = max(lans, rans);
if (lans - rans >= EPS)
r = rmid;
else
l = lmid;
}
// cout << x << ' ' << l << ' ' << ans << '\n';
return ans;
}
void solve()
{
cin >> n;
p.resize(n + 5);
c.resize(n + 5);
for (int i = 1; i <= n; ++i)
cin >> p[i] >> c[i];
long double l = 0, r = 1000000;
long double lans = get(l), rans = get(r);
long double ans = max(lans, rans);
for (int _ = 0; _ < 200; ++_) {
long double lmid = l + (r - l) / 3;
long double rmid = r - (r - l) / 3;
lans = get(lmid), rans = get(rmid);
ans = max(lans, rans);
if (lans - rans >= EPS)
r = rmid;
else
l = lmid;
}
// cout << f(1 / .6L, 1.9) << '\n';
// cout << get(1 / .6L) << '\n';
cout << fixed << setprecision(10) << ans << '\n';
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int T = 1;
while (T--)
solve();
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 3ms
memory: 3920kb
input:
2 1 15 0 10
output:
9.9999999996
result:
ok found '10.0000000', expected '10.0000000', error '0.0000000'
Test #2:
score: 0
Accepted
time: 3ms
memory: 3984kb
input:
3 0.4 100 0.5 100 0.6 100
output:
33.3333333331
result:
ok found '33.3333333', expected '33.3333333', error '0.0000000'
Test #3:
score: 0
Accepted
time: 3ms
memory: 3924kb
input:
1 0 1
output:
-0.0000000001
result:
ok found '-0.0000000', expected '0.0000000', error '0.0000000'
Test #4:
score: 0
Accepted
time: 3ms
memory: 3844kb
input:
2 1 0 1 100
output:
-0.0000000002
result:
ok found '-0.0000000', expected '0.0000000', error '0.0000000'
Test #5:
score: 0
Accepted
time: 3ms
memory: 3980kb
input:
1 0.5 100
output:
0.0000000000
result:
ok found '0.0000000', expected '0.0000000', error '-0.0000000'
Test #6:
score: 0
Accepted
time: 3ms
memory: 3980kb
input:
3 0.4 100 0.6 100 0.6 100
output:
0.0000000000
result:
ok found '0.0000000', expected '0.0000000', error '-0.0000000'
Test #7:
score: 0
Accepted
time: 0ms
memory: 3908kb
input:
3 0.2 100 0.2 100 0.8 100
output:
49.9999999998
result:
ok found '50.0000000', expected '50.0000000', error '0.0000000'
Test #8:
score: 0
Accepted
time: 3ms
memory: 3872kb
input:
2 0.999999 1000000 0.999998 2
output:
0.9999989997
result:
ok found '0.9999990', expected '0.9999990', error '0.0000000'
Test #9:
score: 0
Accepted
time: 3ms
memory: 3960kb
input:
2 0 100000 0.000001 1
output:
-0.0000000001
result:
ok found '-0.0000000', expected '0.0000000', error '0.0000000'
Test #10:
score: 0
Accepted
time: 3ms
memory: 3908kb
input:
2 0 1000000000 0.000001 1
output:
1.0000000000
result:
ok found '1.0000000', expected '1.0000000', error '0.0000000'
Test #11:
score: -100
Time Limit Exceeded
input:
1000000 0.375733 595197307 0.505261 377150668 0.517039 15795246 0.448099 228176467 0.529380 871983979 0.905546 876268308 0.095891 272104456 0.500302 916153337 0.128705 355768079 0.070600 78747362 0.444107 466118868 0.194987 298494965 0.462293 593292779 0.287909 838058266 0.237226 934603199 0.391909 ...