Submission #855462

#	Time	Username	Problem	Language	Result	Execution time	Memory
855462		RiverFlow	Watching (JOI13_watching)	C++14	50 / 100	30 ms	10848 KiB

watching

#include <bits/stdc++.h>

#define nl "\n"
#define no "NO"
#define yes "YES"
#define fi first
#define se second
#define vec vector
#define task "main"
#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)
#define unq(x) sort(all(x)); x.resize(unique(all(x)) - x.begin())

using namespace std;

template<typename U, typename V> bool maxi(U &a, V b) {
    if (a < b) { a = b; return 1; } return 0;
}
template<typename U, typename V> bool mini(U &a, V b) {
    if (a > b || a == -1) { a = b; return 1; } return 0;
}

const int N = (int)100 + 9;
const int mod = (int)1e9 + 7;

void prepare(); void main_code();

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    const bool MULTITEST = 0; prepare();
    int num_test = 1; if (MULTITEST) cin >> num_test;
    while (num_test--) { main_code(); }
}

void prepare() {};

int dp[N][N][N], a[N];

void main_code() {
    int n, p, q; cin >> n >> p >> q;
    for(int i = 1; i <= n; ++i) cin >> a[i];
    sort(a + 1, a + n + 1);
    if (p + q >= n) evoid(1);

    memset(dp, -1, sizeof dp);

    dp[0][0][0] = 0;

    FOR(i, 1, n) FOR(j, 0, p) FOR(k, 0, q) {
        FOR(z, 1, i) {
            if (j > 0 and dp[z - 1][j - 1][k] != -1)
                mini(dp[i][j][k], max(dp[z - 1][j - 1][k], a[i] - a[z] + 1));
            if (k > 0 and dp[z - 1][j][k - 1] != -1)
                mini(dp[i][j][k], max(dp[z - 1][j][k - 1], (a[i] - a[z] + 2) / 2));
        }
    }

    int res = INT_MAX;
    FOR(j, 0, p) FOR(k, 0, q) if (dp[n][j][k] != -1)
        res = min(res, dp[n][j][k]);
    cout << res;
}


/*     Let the river flows naturally     */

Compilation message (stderr)

watching.cpp: In function 'int main()':
watching.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 50 / 50
• Subtask 2: 0 / 50