백준 알고리즘 18353번 : 병사 배치하기

링크

https://www.acmicpc.net/problem/18353

sol1) LIS

#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#include <ext/rope>
#define fastio ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
using namespace std;
using namespace __gnu_cxx;

#define X first
#define Y second
#define int int64_t
#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define Compress(v) sort(all(v)), (v).erase(unique(all(v)), (v).end())
#define OOB(x, y) ((x) < 0 || (x) >= n || (y) < 0 || (y) >= m)
#define IDX(v, x) (lower_bound(all(v), x) - (v).begin())
#define debug(x) cout << (#x) << ": " << (x) << '\n'

using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using tii = tuple<int, int, int>;
template <typename T>
using wector = vector<vector<T>>;

int32_t main(){
	fastio;
	int n; cin >> n;
	vector<int> LIS,v(n);
	for(auto& i : v) cin >> i;
	reverse(all(v));
	for(int i = 0; i < n; i++){
		if(LIS.empty() || LIS.back() < v[i]) LIS.push_back(v[i]);
		else *lower_bound(LIS.begin(), LIS.end(), v[i]) = v[i];
	}
	cout << n - LIS.size() << "\n";
}