Submission #567539

#	Time	Username	Problem	Language	Result	Execution time	Memory
567539		ngpin04	Boxes with souvenirs (IOI15_boxes)	C++17	10 / 100	1 ms	340 KiB

boxes

#include <bits/stdc++.h>
#include "boxes.h"
#define fi first
#define se second
#define mp make_pair
#define TASK ""
#define bit(x) (1LL << (x))
#define getbit(x, i) (((x) >> (i)) & 1)
#define ALL(x) (x).begin(), (x).end() 
using namespace std;
template <typename T1, typename T2> bool mini(T1 &a, T2 b) {
    if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maxi(T1 &a, T2 b) {
    if (a < b) {a = b; return true;} return false;
}
mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());

int rand(int l, int r) {
    return l + rd() % (r - l + 1);
}
const int N = 1e6 + 5; 
const int oo = 1e9;
const long long ooo = 1e18;
const int mod = 1e9 + 7; // 998244353;
const long double pi = acos(-1);

int pre[N];
int suf[N];
int a[N];
int n,k,l;

long long solve() {
    sort(a + 1, a + n + 1);
    for (int i = 1; i <= n; i++)
        pre[i] = 2 * a[i] + pre[max(0, i - k)];

    for (int i = n; i >= 1; i--)
        suf[i] = 2 * (l - a[i]) + suf[min(n + 1, i + k)];

    // for (int i = 1; i <= n; i++)
    //     cerr << pre[i] << " " << suf[i] << "\n";

    long long ans = 1LL * ((n + k - 1) / k) * l;
    for (int t = 0; t * k < n; t++) {
        int lef = n - t * k;
        int lo = 0;
        int hi = lef + 1;
        while (hi - lo > 1) {
            int mid = (lo + hi) >> 1;
            int l = mid;
            int r = lef - mid;
            if (pre[l] < suf[n - r + 1])
                lo = mid;
            else
                hi = mid;
        }
        mini(hi, lef);
        for (int i = lo; i <= hi; i++) {
            int x = i;
            int y = lef - i;
            mini(ans, 1LL * t * l + pre[x] + suf[n - y + 1]);
        }
    }
    return ans;
}

long long delivery(int N, int K, int L, int p[]) {
    n = N;
    k = K;
    l = L;
    for (int i = 0; i < n; i++) 
        a[i + 1] = p[i];
    return solve();
}

//#include "grader.cpp"

Compilation message (stderr)

boxes.cpp: In function 'int rand(int, int)':
boxes.cpp:20:14: warning: conversion from 'std::mersenne_twister_engine<long unsigned int, 64, 312, 156, 31, 13043109905998158313, 29, 6148914691236517205, 17, 8202884508482404352, 37, 18444473444759240704, 43, 6364136223846793005>::result_type' {aka 'long unsigned int'} to 'int' may change value [-Wconversion]
   20 |     return l + rd() % (r - l + 1);
      |            ~~^~~~~~~~~~~~~~~~~~~~
boxes.cpp: In function 'long long int solve()':
boxes.cpp:51:17: warning: declaration of 'l' shadows a global declaration [-Wshadow]
   51 |             int l = mid;
      |                 ^
boxes.cpp:31:9: note: shadowed declaration is here
   31 | int n,k,l;
      |         ^
boxes.cpp: In function 'long long int delivery(int, int, int, int*)':
boxes.cpp:68:24: warning: declaration of 'N' shadows a global declaration [-Wshadow]
   68 | long long delivery(int N, int K, int L, int p[]) {
      |                    ~~~~^
boxes.cpp:22:11: note: shadowed declaration is here
   22 | const int N = 1e6 + 5;
      |           ^

• Subtask 1: 0 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 15
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30