Submission #874240

#	Time	Username	Problem	Language	Result	Execution time	Memory
874240		tsumondai	Stove (JOI18_stove)	C++14	100 / 100	16 ms	3312 KiB

stove

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

#define int long long
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define foru(i, l, r) for(int i = l; i <= r; i++)
#define ford(i, r, l) for(int i = r; i >= l; i--)
#define __TIME  (1.0 * clock() / CLOCKS_PER_SEC)

typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;
 
const int N = 1e5 + 5;
 
const int oo = 1e18, mod = 1e9 + 7;
 
int n, m, k, t[N];
string s;
vector<int> dist;

/*
sieu tom tat: dươc phep chon toi da k diem sao cho tong cua cac khoang cach
o cac diuem khong duoc chon la no nhat
liet ke ra k cac khoang cach giua 1 dong diem day
sort =)))
ok let's try
subtask 1: bitmask O(2^20)
subtask 2: dp (N*N)
subtask 3: greedy hoac la dp with data structure gi day
*/

void process() {
	int res=t[n]-t[1]+1;
	//cout << res << '\n';
	foru(i,2,n) dist.pb(t[i]-t[i-1]);
	sort(dist.begin(), dist.end(), greater<int>());
	/*for (auto x: dist) cout << x << ' ';
	cout << '\n';*/
	foru(i,0,k-2) res-=(dist[i]-1);
	cout << res;
	return;
}

signed main() {
    cin.tie(0)->sync_with_stdio(false);
    //freopen(".inp", "r", stdin);
    //freopen(".out", "w", stdout);
	cin >> n >> k;
	foru(i,1,n) cin >> t[i];
    process();
    cerr << "Time elapsed: " << __TIME << " s.\n";
    return 0;
}

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