Submission #1218853

#	Time	Username	Problem	Language	Result	Execution time	Memory
1218853		CodeLakVN	Collecting Stamps 3 (JOI20_ho_t3)	C++20	15 / 100	19 ms	5564 KiB

ho_t3

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

#define task "main"
#define no "NO"
#define yes "YES"
#define F first
#define S second
#define vec vector
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)

const int MAX_N = (int)2e2 + 4;
const int INF = (int)1e9 + 1408;

int n, l;
int pos[MAX_N], timeLimit[MAX_N];

namespace sub2 {
    ii dp[1 << 15][20];
    
    int dist(int x, int y) {
        if (x > y) swap(x, y);
        return min(y - x, x + l - y);
    }

    void solve() {
        FOR(mask, 1, (1 << n) - 1) {
            FOR(i, 0, n - 1) {
                dp[mask][i] = {INF, 0};
                if (!((mask >> i) & 1)) continue;
                if (__builtin_popcount(mask) == 1) {
                    dp[mask][i].F = dist(0, pos[i + 1]);
                    if (dp[mask][i].F <= timeLimit[i + 1]) dp[mask][i].S = 1;
                    continue;
                }
                int preMask = (mask ^ (1 << i));
                FOR(last, 0, n - 1) {
                    if (!((preMask >> last) & 1)) continue;
                    int tmp = dp[preMask][last].F + dist(pos[last + 1], pos[i + 1]);
                    if (tmp <= timeLimit[i + 1]) {
                        if (dp[preMask][last].S + 1 > dp[mask][i].S)
                            dp[mask][i] = {tmp, dp[preMask][last].S + 1};
                        else if (dp[preMask][last].S + 1 == dp[mask][i].S)
                            dp[mask][i].F = min(dp[mask][i].F, tmp);
                    }
                }
            }
        }
        int ans = 0;
        FOR(mask, 1, (1 << n) - 1) FOR(i, 0, n - 1) ans = max(ans, dp[mask][i].S);

        cout << ans << "\n";
    }
}

void solve() {
    cin >> n >> l;
    FOR(i, 1, n) cin >> pos[i];
    FOR(i, 1, n) cin >> timeLimit[i];
    
    if (n <= 15) sub2::solve();
}

int32_t main() {
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    bool multitest = 0;
    int numTest = 1;
    if (multitest) cin >> numTest;

    while (numTest--) {
        solve();
    }

    return 0;
}

/* Lak lu theo dieu nhac!!!! */

Compilation message (stderr)

ho_t3.cpp: In function 'int32_t main()':
ho_t3.cpp:72:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
ho_t3.cpp:73:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 75