Submission #1277352

#	Time	Username	Problem	Language	Result	Execution time	Memory
1277352		adscoding	구경하기 (JOI13_watching)	C++20	100 / 100	247 ms	15628 KiB

watching

#include <bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define BIT(mask, x) ((mask >> (x)) & 1)
#define FOR(i, a, b) for (int i = a, _b = b; i <= _b; ++i)
#define FORD(i, a, b) for (int i = a, _b = b; i >= _b; --i)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int maxn = 2e3 + 3;
int n, nbig, nsmall, a[maxn];


bool check(const int &w)
{
    vector<vector<int>> dp(n + 1, vector<int>(nbig + 1, 1e9));
    dp[0][0] = 0;
    int jbig = 1, jsmall = 1;
    
    FOR(i, 1, n)
    {
        while (jbig < i && a[i] - a[jbig] + 1 > 2 * w) ++jbig;
        while (jsmall < i && a[i] - a[jsmall] + 1 > w) ++jsmall;
        FOR(big, 0, nbig)
        {
            if (big) dp[i][big] = min(dp[i][big], dp[jbig - 1][big - 1]);
            if (dp[jsmall - 1][big] < nsmall) dp[i][big] = min(dp[i][big], dp[jsmall - 1][big] + 1);
        }
    }
    FOR(i, 0, nbig) if (dp[n][i] <= nsmall) return true;
    return false;
}

void solve()
{
    cin >> n >> nsmall >> nbig;
    nsmall = min(nsmall, n);
    nbig = min(nbig, n);
    while (nbig > 0 && nbig + nsmall > n) --nbig;

    FOR(i, 1, n) cin >> a[i];
    sort(a + 1, a + n + 1);
    
    int l = 1, r = 1e9;
    while (l <= r)
    {
        int mid = l + r >> 1;
        if (check(mid)) r = mid - 1;
        else l = mid + 1;
    }
    cout << l;
}

signed main()
{
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    #define TASK "TEST"
    if (fopen(TASK".INP", "r"))
    {
        freopen(TASK".INP", "r", stdin);
        freopen(TASK".OUT", "w", stdout);
    }
    solve();
    return 0;
}

/* NOTES:   

*/

Compilation message (stderr)

watching.cpp: In function 'int main()':
watching.cpp:62:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |         freopen(TASK".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:63:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |         freopen(TASK".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 50 / 50
• Subtask 2: 50 / 50