Submission #1124619

#	Time	Username	Problem	Language	Result	Execution time	Memory
1124619		wibulord	Mobile (BOI12_mobile)	C++20	100 / 100	373 ms	16096 KiB

mobile

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define pb emplace_back
#define ii pair<int, int>
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define sz(s) (int)((s).size())
#define all(a) a.begin(), a.end()
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define F0R(i, b) for (int i = 0, _b = (b); i < _b; ++i)
#define FORd(i, a, b) for (int i = (a), _b = (b); i >= _b; --i)
#define F0Rd(i, b) for (int i = (b)-1; i >= 0; i--)
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
using namespace std;

template<typename T1,typename T2> bool ckmax(T1 &x,const T2 &y){if(x<y){x=y; return 1;} return 0;}
template<typename T1,typename T2> bool ckmin(T1 &x,const T2 &y){if(y<x){x=y; return 1;} return 0;}

const int MOD = (int)1e9 + 7;
const int mod = 998244353;
const int N = 1e6 + 10, M = 18;
const long long INF = (long long)4e18 + 11;

/*
     /\_/\
    (= ._.)
    / >?  \>$
*/

int n, L;
long long x[N], y[N];

#define SQR(x) ((x) * (x))
bool check(double d){
    double lst = 0;
    FOR(i, 1, n){
        double LEN = sqrt(SQR(d) - SQR(y[i]));
        if(x[i] - LEN <= lst) lst = max(lst, x[i] + LEN);
    }
    return lst >= L;
}

void sol(void){
    cin >> n >> L;
    for(int i = 1; i <= n; i++) cin >> x[i] >> y[i];
    double l = 0, r = 1.5e9;
    while(l + 1e-3 < r){
        double m = (l + r) / 2;
        if(check(m)) r = m;
        else l = m;
    }
    cout << fixed << setprecision(4) << r << '\n';
}

signed main(void){
    #define TASK "nhap"
    if(fopen(TASK".inp", "r")){
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    int t = 1;
//    cin >> t;
    while(t--) sol();
    cerr << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << " ms\n";
}

Compilation message (stderr)

mobile.cpp: In function 'int main()':
mobile.cpp:60:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
mobile.cpp:61:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 4 / 4
• Subtask 3: 4 / 4
• Subtask 4: 4 / 4
• Subtask 5: 4 / 4
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• Subtask 19: 5 / 5
• Subtask 20: 5 / 5
• Subtask 21: 5 / 5