606C - Sorting Railway Cars - CodeForces Solution

// Problem: C. Сортировка вагонов
// Contest: Codeforces - Codeforces Round 335 (Div. 2)
// URL: https://codeforces.com/contest/606/problem/C
// Memory Limit: 256 MB
// Time Limit: 2000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define pb push_back
#define F first
#define S second
#define in insert
using namespace std;
typedef long long ll;

typedef unsigned long long ull;

const int N = 1e6 + 123;

const int P = 320;

const int inf = 1e9 + 7;

ll n, k;

ll a[N];

ll dp[N];

void solve() {
    cin >> n;
	
	
	for(int i = 1; i <= n; i++) {
		cin >> a[i];
	}  
	
	dp[0] = 0;
	
	ll mx = 0;
	
	for(int i = 1; i <= n; i++) {
		dp[a[i]] = dp[a[i] - 1] + 1;
		
		if(mx < dp[a[i]]) {
			mx = dp[a[i]];
		}
	}
	
	cout << n - mx << '\n';
}
// 28 37 48 49 55 56 57 58 67 9

// 9 + 1 +

int main() {

    //freopen("knight.in",   "r", stdin);

    //freopen("knight.out", "w", stdout);

    ios_base::sync_with_stdio(0);

    cin.tie(0);

    cout.tie(0);

    ll tt = 1;

    //cin >> tt;

    while(tt--) {
        solve();
    }
}