Submission #1244736

#	Time	Username	Problem	Language	Result	Execution time	Memory
1244736		nasjes	Group Photo (JOI21_ho_t3)	C++20	64 / 100	49 ms	328 KiB

Main

#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
const ll dim = 3*1e3+7;
//const ll mod = 1e9 + 7;
const ll inf = 1e18 + 77;
#define endl "\n"
#define fi first
#define pb push_back
#define se second
#define vll vector<ll>

ll n, m;
ll ext[dim], a[dim], dp[dim], b[dim], rev[dim];


int main() {
    ll k, t, u0, v0;
    cin>>n;
    for(int i=1; i<=n; i++){
        cin>>b[i];
        a[b[i]]=i;
    }
    dp[1]=0;
    for(int i=1; i<=n; i++){
        ll sum=0;
        dp[i]=inf;
        ll ans=0;
        ll cur=0;
        for(int j=1; j<i; j++){
            if(a[j]>a[i])cur++;
            dp[j]+=cur;
        }

        for(int j=i; j>=1; j--) {
            sum+=rev[j];
            if(a[j]<a[i])ans++;
            dp[i]=min(dp[j-1]+sum+ans, dp[i]);
           // cout<<dp[j-1]<<" "<<add<<endl;
        }
        for(int j=i-1;j>=1; j--){
            if(a[j]<a[i]){rev[j]++; }
        }

    }
    cout<<dp[n]<<endl;

    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 32 / 32
• Subtask 4: 20 / 20
• Subtask 5: 0 / 36