Submission #1009735

#	Time	Username	Problem	Language	Result	Execution time	Memory
1009735		ProtonDecay314	Boxes with souvenirs (IOI15_boxes)	C++17	20 / 100	1 ms	600 KiB

boxes

/*
???

*/
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pi;
typedef pair<ll, ll> pll;
typedef vector<pi> vpi;
typedef vector<pll> vpll;
#define first fi;
#define second se;

ll delivery(int intn, int intk, int intl, int pos_int[]) {
    ll n = intn, k = intk, l = intl;
    vll pos(n, 0ll);
    for(ll i = 0; i < n; i++) {
        pos[i] = pos_int[i];
    }

    ll ans = 0ll;
    if(k == 1) {
        for(ll i = 0; i < n; i++) {
            ans += min(pos[i], l - pos[i]) << 1ll;
        }
    } else if(k == n) {
        sort(pos.begin(), pos.end());
        ll min_not_zero = -1ll;
        ll max_left = 0ll;
        ll max_right = l;
        for(ll i = 0; i < n; i++) {
            if(pos[i] != 0ll) {
                min_not_zero = pos[i];
                break;
            }
        }
        for(ll i = 0; i < n; i++) {
            if(pos[i] > (l >> 1ll) || ((l & 1) == 0ll && pos[i] == (l >> 1ll))) max_right = min(max_right, pos[i]);
            if(l - pos[i] > (l >> 1ll)) max_left = max(max_left, pos[i]);
        }
        // bool gthalfexists = pos[n - 1ll] > (l >> 1ll);
        // bool lthalfexists = (min_not_zero != -1ll) && (l - min_not_zero > (l >> 1ll));

        // if(gthalfexists && lthalfexists) {
        //     ans = min(l, (l - min_not_zero + pos[n - 1]) << 1ll);
        // } else if(gthalfexists) {
        //     ans = (l - min_not_zero) << 1ll;
        // } else {
        //     ans = pos[n - 1] << 1ll;
        // }

        ans = min(l, (l - max_right + max_left) << 1ll);
    }
    return ans;
}

#ifdef DEBUG
int main() {
    cin.tie(nullptr);
    cout.tie(nullptr);
    ios_base::sync_with_stdio(false);

    int n, k, l;
    cin >> n >> k >> l;

    vi positions(n, 0);
    for(int& pos : positions) {
        cin >> pos;
    }

    cout << delivery(n, k, l, &positions[0]) << endl;
}
#endif

Compilation message (stderr)

boxes.cpp: In function 'll delivery(int, int, int, int*)':
boxes.cpp:33:12: warning: variable 'min_not_zero' set but not used [-Wunused-but-set-variable]
   33 |         ll min_not_zero = -1ll;
      |            ^~~~~~~~~~~~

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