Submission #835975

#	Time	Username	Problem	Language	Result	Execution time	Memory
835975		maomao90	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	546 ms	97068 KiB

tickets

// I can do all things through Christ who strengthens me
// Philippians 4:13

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

#define REP(i, j, k) for (int i = j; i < (k); i++)
#define RREP(i, j, k) for (int i = j; i >= (k); i--)

template <class T>
inline bool mnto(T &a, const T b) {return a > b ? a = b, 1 : 0;}
template <class T>
inline bool mxto(T &a, const T b) {return a < b ? a = b, 1 : 0;}

typedef long long ll;
typedef long double ld;
#define FI first
#define SE second
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
#define ALL(x) x.begin(), x.end()
#define SZ(x) (int) x.size()
#define pb push_back
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef tuple<int, int, int> iii;
typedef vector<iii> viii;

#ifndef DEBUG
#define cerr if (0) cerr
#endif

const int INF = 1000000005;
const ll LINF = 1000000000000000005;
const int MAXN = 1505;

int n, m, k;
vector<vi> x, s;
ii diff[MAXN];
vi grp[MAXN][2];
bool used[MAXN * MAXN];
ll ans;
int l[MAXN], r[MAXN];
priority_queue<ii> pq;

ll find_maximum(int _k, vector<vi> _x) {
    k = _k; x = _x;
    n = SZ(x); m = SZ(x[0]);
    s = vector<vi>(n, vi(m, -1));
    if (1 || k == m) {
        viii vx;
        REP (i, 0, n) {
            r[i] = m - k;
            l[i] = 0;
            REP (j, m - k, m) {
                ans += x[i][j];
            }
            pq.push({-x[i][r[i]] - x[i][l[i]], i});
        }
        REP (z, 0, n / 2 * k) {
            auto [v, i] = pq.top(); pq.pop();
            ans += v;
            r[i]++; l[i]++;
            if (r[i] != m) {
                pq.push({-x[i][r[i]] - x[i][l[i]], i});
            }
        }
        REP (i, 0, n) {
            REP (j, 0, l[i]) {
                grp[i][0].pb(j);
            }
            REP (j, r[i], m) {
                grp[i][1].pb(j);
            }
        }
        /*
        sort(ALL(vx));
        int cnt = 0;
        REP (p, 0, n * m) {
            auto [x, i, j] = vx[p];
            if (SZ(grp[i][0]) + SZ(grp[i][1]) >= k || used[p]) {
                continue;
            }
            used[p] = 1;
            cnt++;
            ans -= x;
            grp[i][0].pb(j);
            if (cnt >= n / 2 * k) {
                break;
            }
        }
        assert(cnt == n / 2 * k);
        cnt = 0;
        RREP (p, n * m - 1, 0) {
            auto [x, i, j] = vx[p];
            if (SZ(grp[i][0]) + SZ(grp[i][1]) >= k || used[p]) {
                continue;
            }
            used[p] = 1;
            cnt++;
            ans += x;
            grp[i][1].pb(j);
            if (cnt >= n / 2 * k) {
                break;
            }
        }
        assert(cnt == n / 2 * k);
        */
        REP (z, 0, k) {
            int cnt[2] = {0, 0};
            REP (i, 0, n) {
                if (grp[i][0].empty()) {
                    cnt[1]++;
                    int j = grp[i][1].back(); grp[i][1].pop_back();
                    s[i][j] = z;
                } else if (grp[i][1].empty()) {
                    cnt[0]++;
                    int j = grp[i][0].back(); grp[i][0].pop_back();
                    s[i][j] = z;
                }
            }
            REP (i, 0, n) {
                if (grp[i][0].empty() || grp[i][1].empty()) {
                    continue;
                }
                REP (l, 0, 2) {
                    if (cnt[l] == n / 2) {
                        continue;
                    }
                    cnt[l]++;
                    int j = grp[i][l].back(); grp[i][l].pop_back();
                    s[i][j] = z;
                    break;
                }
            }
        }
        allocate_tickets(s);
        return ans;
    }
    REP (i, 0, n) {
        l[i] = 0, r[i] = m - 1;
    }
    REP (z, 0, k) {
        REP (i, 0, n) {
            ans += x[i][r[i]];
            diff[i] = {x[i][r[i]] + x[i][l[i]], i};
            s[i][r[i]--] = z;
        }
        sort(diff, diff + n);
        REP (i, 0, n / 2) {
            ans -= diff[i].FI;
            s[diff[i].SE][++r[diff[i].SE]] = -1;
            s[diff[i].SE][l[diff[i].SE]++] = z;
        }
    }
    allocate_tickets(s);
    return ans;
}

• Subtask 1: 11 / 11
• Subtask 2: 16 / 16
• Subtask 3: 14 / 14
• Subtask 4: 14 / 14
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23
• Subtask 7: 10 / 10