| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 1047186 |
2024-08-07T10:11:10 Z |
Requiem |
Balloons (CEOI11_bal) |
C++17 |
|
2000 ms |
13884 KB |
#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#define MOD 1000000007
#define inf 1e18
#define fi first
#define se second
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define FORD(i,a,b) for(int i=a;i>=b;i--)
#define sz(a) ((int)(a).size())
#define endl '\n'
#define pi 3.14159265359
#define TASKNAME "balloon"
using namespace std;
/**Debugging Tool **/
void __print(int x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
/*----------------------------------*/
/** Vector nhieu chieu **/
template<int D, typename T>
struct Vec: public vector<Vec<D - 1, T>>{
static_assert(D >= 1, "vector dimensions must be greater than 0");
template<typename... Args>
Vec(int n = 0, Args... args): vector<Vec<D - 1, T>>(n, Vec<D - 1, T>(args...)){
}
};
template<typename T>
struct Vec<1, T>: public vector<T> {
Vec(int n = 0, const T& val = T()): vector<T>(n, val) {};
};
/*--------------------------------*/
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
typedef vector<int> vi;
#define eps 1e-4
/**
* Cho n quả bóng với 2 thông số là Xi và Ri, tương ứng là vị trí bơm và bán kính bơm tối đa.
* Ta bơm tuần tự từ quả bóng thứ 1 đến quả bóng thứ n.
* Với quả bóng thứ i, ta bơm cho đến khi nó chạm vào quả bóng khác hoặc nó đạt bán kính tối đa
* Giả sử ta đang có cấu hình là (x1, r1), (x2, r2), ... Khi thêm vào (xn, rn) thì bài toán
sẽ thay đổi ntn
* Với n <= 2000, ta có thể duyệt n^2 để tìm ra bán kính của quả bóng
*
* bằng cách lấy min((x - xj)^2 / (4 * rj))
* Khi n lớn lên, ta sẽ cần một cách làm thông minh hơn bằng cách chỉ duyệt qua những vị trí cần thiết.
*/
const int MAXN = 3e5 + 9;
struct balloon{
int position;
int maxDiameter;
} B[MAXN];
int n;
void input(){
cin >> n;
for(int i = 1; i <= n; i++){
cin >> B[i].position >> B[i].maxDiameter;
}
}
namespace subtask1{
bool check(){
return n <= 2000;
}
double currentDiameter[MAXN];
//1 vị trí là không cần thiết nếu như sau có thằng lớn hơn nó.
void solve(){
for(int i = 1; i <= n; i++){
if (i == 1) currentDiameter[i] = B[i].maxDiameter;
else{
currentDiameter[i] = B[i].maxDiameter;
for(int j = 1; j < i; j++){
int x1 = B[j].position;
int x2 = B[i].position;
minimize(currentDiameter[i], 1.0 * (x1 - x2) * (x1 - x2) / (4 * currentDiameter[j]));
debug(1.0 * (x1 - x2) * (x1 - x2) / (4 * currentDiameter[j]));
}
}
cout << setprecision(3) << fixed << currentDiameter[i] << endl;
}
cout << endl;
}
}
namespace subtask2{
bool check(){
return true;
}
vector<int> stk;
double currentDiameter[MAXN];
double calc(double x1, double x2, double r1){
return (x1 - x2) * (x1 - x2) / (4 * r1);
}
void solve(){
for(int i = 1; i <= n; i++){
if (i == 1) {
currentDiameter[i] = B[i].maxDiameter;
stk.pb(i);
}
else{
currentDiameter[i] = B[i].maxDiameter;
for(int j = 0; j < stk.size(); j++){
int x1 = B[stk[j]].position;
int x2 = B[i].position;
minimize(currentDiameter[i], 1.0 * (x1 - x2) * (x1 - x2) / (4 * currentDiameter[stk[j]]));
double c = 1.0 * (x1 - x2) * (x1 - x2) / (4.0 * currentDiameter[stk[j]]);
// cout << setprecision(3) << "?"<<fixed << (x1 - x2) * (x1 - x2) / (4.0 * currentDiameter[stk[j]]) << endl;
}
// cout << endl;
while(!stk.empty() and currentDiameter[i] > currentDiameter[stk.back()] + eps){
stk.pop_back();
}
stk.pb(i);
}
cout << setprecision(3) << fixed << currentDiameter[i] << endl;
}
cout << endl;
}
}
main()
{
fast;
if (fopen(TASKNAME".inp","r")){
freopen(TASKNAME".inp","r",stdin);
freopen(TASKNAME".out","w",stdout);
}
input();
// if (subtask1::check()) return subtask1::solve(), 0;
if (subtask2::check()) return subtask2::solve(), 0;
}
/**
Warning:
- MLE / TLE?
- Gioi han mang?
- Gia tri max phai luon gan cho -INF
- long long co can thiet khong?
- tran mang.
- code can than hon
- Nho sinh test de tranh RTE / TLE
--> Coi lai truoc khi nop
**/
Compilation message
bal.cpp: In function 'void subtask2::solve()':
bal.cpp:142:34: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
142 | for(int j = 0; j < stk.size(); j++){
| ~~^~~~~~~~~~~~
bal.cpp:146:28: warning: unused variable 'c' [-Wunused-variable]
146 | double c = 1.0 * (x1 - x2) * (x1 - x2) / (4.0 * currentDiameter[stk[j]]);
| ^
bal.cpp: At global scope:
bal.cpp:160:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
160 | main()
| ^~~~
bal.cpp: In function 'int main()':
bal.cpp:164:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
164 | freopen(TASKNAME".inp","r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
bal.cpp:165:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
165 | freopen(TASKNAME".out","w",stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
4696 KB |
10 numbers |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
4440 KB |
2 numbers |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
4444 KB |
505 numbers |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
2 ms |
4444 KB |
2000 numbers |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
14 ms |
4700 KB |
20000 numbers |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
254 ms |
7616 KB |
50000 numbers |
| 2 |
Correct |
867 ms |
8404 KB |
49912 numbers |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
407 ms |
7764 KB |
100000 numbers |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
552 ms |
9812 KB |
115362 numbers |
| 2 |
Execution timed out |
2035 ms |
11992 KB |
Time limit exceeded |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
631 ms |
10064 KB |
154271 numbers |
| 2 |
Execution timed out |
2037 ms |
13884 KB |
Time limit exceeded |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
247 ms |
10324 KB |
200000 numbers |
| 2 |
Execution timed out |
2101 ms |
13780 KB |
Time limit exceeded |
| 3 |
Halted |
0 ms |
0 KB |
- |
