Submission #1286805

#	Time	Username	Problem	Language	Result	Execution time	Memory
1286805		shidou26	Balloons (CEOI11_bal)	C++20	100 / 100	233 ms	11420 KiB

bal

#include <bits/stdc++.h>
using namespace std;

#ifdef KURUMI
    #include "algo/debug.h"
#endif

#define endl '\n'
#define fi first
#define se second
#define sz(v) (int)v.size()
#define all(v) v.begin(), v.end()
#define filter(v) v.resize(unique(all(v)) - v.begin())
#define dbg(x) "[" #x << " = " << x << "]"

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template<typename T1, typename T2> T2 rand(T1 l, T2 r) {
    return uniform_int_distribution<T2>(l, r)(rng);
}
template<typename T1, typename T2> T2 wrand(T1 l, T2 r, int seed) {
    if(seed == 0) return rand(l, r);
    else return (seed > 0 ? max(rand(l, r), wrand(l, r, seed - 1)) : min(rand(l, r), wrand(l, r, seed + 1)));
}

template<typename T> bool maximize(T &a, T b) {
    if(a < b) {
        a = b;
        return true;
    }else return false;
}
template<typename T> bool minimize(T &a, T b) {
    if(a > b) {
        a = b;
        return true;
    }else return false;
}

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, int> pli;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> tp3;

const int N = 2e5 + 3;

int n;
ld x[N], limr[N];

void input() {
    cin >> n;

    for(int i = 1; i <= n; i++) {
        cin >> x[i] >> limr[i];
    }
}

ld distance(ld x, ld y, ld a, ld b) {
    return sqrt((x - a) * (x - a) + (y - b) * (y - b));
}

namespace subtask_1 {
    bool approve() {
        return n <= 2000;
    }

    ld rad[N];

    void execute() {
        for(int i = 1; i <= n; i++) {
            if(i == 1) rad[i] = limr[i];
            else {
                ld l = 0, r = limr[i];
                for(int rep = 1; rep <= 50; rep++) {
                    ld mid = (l + r) / 2.0;

                    bool passed = true;
                    for(int j = 1; j < i; j++) {
                        if(distance(x[i], mid, x[j], rad[j]) < rad[j] + mid) {
                            passed = false;
                            break;
                        }
                    }

                    if(passed) rad[i] = mid, l = mid;
                    else r = mid;
                }
            }
        }

        for(int i = 1; i <= n; i++)
            cout << fixed << setprecision(3) << rad[i] << endl;
    }
}

namespace subtask_2 {
    bool approve() {
        return true;
    }

    ld rad[N];

    ld calc(int i, int j) {
        return ((x[i] - x[j]) * (x[i] - x[j]) / (4 * rad[i]));
    }

    void execute() {
        stack<int> use;
        for(int i = 1; i <= n; i++) {
            rad[i] = limr[i];

            while(!use.empty()) {
                minimize(rad[i], calc(use.top(), i));

                if(rad[i] >= rad[use.top()])
                    use.pop();
                else break;
            }

            use.push(i);
        }

        for(int i = 1; i <= n; i++)
            cout << fixed << setprecision(3) << rad[i] << endl;
    }
}

void process() {
    if(subtask_1::approve()) return subtask_1::execute();
    if(subtask_2::approve()) return subtask_2::execute();
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    #define task "Deeto"
    if(fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }

    int testcase = 1; // cin >> testcase;
    for(int i = 1; i <= testcase; i++) {
        input();
        process();
    }

    cerr << "Saa, watashtachi no deeto hajimemashou" << endl;
    cerr << "Atarashii kiseki wo koko kara hajimeru shining place nee mou ichido kimi to..." << endl;

    return 0;
}

Compilation message (stderr)

bal.cpp: In function 'int main()':
bal.cpp:139:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  139 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bal.cpp:140:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  140 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10