Submission #1123565

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123565		hoainiem	Stove (JOI18_stove)	C++17	100 / 100	22 ms	2632 KiB

stove

#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define task "file"
using namespace std;
const int inf = 1e15;
const int mx = 2e5 + 5;
int n, k;
long long a[mx];
pair<long long,int> dp[mx];
void read(){
    cin >> n >> k;
    for (int i = 1; i <= n; i++){
        cin >> a[i];
    }
    sort(a + 1, a + n + 1);
}

pair<long long, int> choose(pair<long long, int> x, pair<long long, int> y) {
    if (x.first < y.first) {
        return x;
    }
    if (x.first > y.first) {
        return y;
    }
    return (x.second < y.second) ? x : y;
}

void solve(){
    long long l = 0, r = inf;
    long long ans = -1;
    while (l <= r) {
        long long mid = (l + r) / 2;
        dp[1] = {mid + 1, 1};
        for (int i = 2; i <= n; i++){
            dp[i] = choose(make_pair(dp[i - 1].first + 1 + mid, dp[i - 1].second + 1), make_pair(dp[i - 1].first + a[i] - a[i - 1], dp[i - 1].second));
        }
        if (dp[n].second <= k) {
            ans = dp[n].first - mid * k;
            r = mid - 1;
        }
        else {
            l = mid + 1;
        }
    }
    cout << ans;
}
signed main(){
    cin.tie(0)->sync_with_stdio(0);
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    read();
    solve();
}

Compilation message (stderr)

stove.cpp: In function 'int main()':
stove.cpp:51:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   51 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
stove.cpp:52:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50