Submission #1089081

#	Time	Username	Problem	Language	Result	Execution time	Memory
1089081		efishel	Coin Collecting (JOI19_ho_t4)	C++17	37 / 100	357 ms	24352 KiB

joi2019_ho_t4

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vll = vector <ll>;
using ii = pair <ll, ll>;
using vii = vector <ii>;

ll dp[1005][1005];
// dp[a][b]

int main () {
    cin.tie(nullptr) -> sync_with_stdio(false);
    ll n;
    cin >> n;
    vii ve(2*n);
    for (auto &[x, y] : ve) cin >> x >> y;
    // ll ans = 0;
    // auto fclamp = [&](ll l, ll r, ll &val) {
    //     if (val < l) { ans += l-val; val = l; }
    //     if (val > r) { ans += val-r; val = r; }
    // };
    // for (auto &[x, y] : ve) {
    //     fclamp(1, n, x);
    //     fclamp(1, 2, y);
    // }
    sort(ve.begin(), ve.end());
    auto fcost = [&](ll X, ll Y, ll i) {
        auto [x, y] = ve[i];
        return abs(x-X) + abs(y-Y);
    };
    // auto shsw = [&](ll i, ll j) {
    //     return fcost(i, asg[j]) + fcost(j, asg[i]) < fcost(i, asg[i]) + fcost(j, asg[j]);
    // };
    memset(dp, 0x3f, sizeof(dp));
    dp[0][0] = 0; // no coins moved, none to be assigned
    for (ll c1 = 0; c1 <= n; c1++) {
        for (ll c2 = 0; c2 <= n; c2++) {
            ll i = c1+c2-1;
            if (c1 > 0) dp[c1][c2] = min(dp[c1][c2], dp[c1-1][c2] + fcost(c1, 1, i));
            if (c2 > 0) dp[c1][c2] = min(dp[c1][c2], dp[c1][c2-1] + fcost(c2, 2, i));
        }
    }
    cout << dp[n][n] << '\n';
    // for (ll k = 0; k < 2*n; k++) {
    //     for (ll i = 0; i < 2*n; i++) {
    //         for (ll j = 0; j < 2*n; j++) {
    //             if (shsw(i, j)) swap(asg[i], asg[j]);
    //         }
    //     }
    // }
    // for (ll i = 0; i < 2*n; i++) ans += cost(i, asg[i]);
    // cout << ans << '\n';
    return 0;
}
/*
0 0 4 0 1 2
2 0 3 0 0 0

0 0 a 0 b c
d 0 e 0 0 0

d a a b c c
d a a e e e

a a a a b c
d d e e e c

dp[i][a][b] = min cost to reach a state where the prefix
*/

• Subtask 1: 8 / 8
• Subtask 2: 29 / 29
• Subtask 3: 0 / 63