Submission #1087404

#	Time	Username	Problem	Language	Result	Execution time	Memory
1087404		steveonalex	Group Photo (JOI21_ho_t3)	C++17	100 / 100	301 ms	67576 KiB

Main

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

struct FenwickTree{
    int n;
    vector<int> a;

    FenwickTree(int _n){
        n = _n;
        a.resize(n+1);
    }

    void update(int i, int v){
        while(i <= n){
            a[i] += v;
            i += LASTBIT(i);
        }
    }

    int get(int i){
        int ans = 0;
        while(i > 0){
            ans += a[i];
            i -= LASTBIT(i);
        }
        return ans;
    }
};

const int N = 5005, INF = 1e9 + 69;
int n;
int a[N], p[N];
int dp[N];
int cost[N][N];

int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
    clock_t start = clock();

    cin >> n;
    for(int i= 1; i<=n; ++i) cin >> a[i];
    for(int i = 1; i<=n; ++i) p[a[i]] = i;

    FenwickTree bit1(n);
    for(int i = 1; i<=n; ++i){
        FenwickTree bit2(n);
        for(int j = i; j<=n; ++j){
            cost[i][j] = cost[i][j-1];
            cost[i][j] += (i - 1) - bit1.get(p[j]);
            cost[i][j] += bit2.get(p[j]);
            bit2.update(p[j], 1);
        }
        bit1.update(p[i], 1);
    }

    for(int i= 1; i<=n; ++i) dp[i] = INF;
    for(int i = 0; i<n; ++i){
        for(int j = i + 1; j <= n; ++j) 
            minimize(dp[j], dp[i] + cost[i+1][j]);
    }

    cout << dp[n] << "\n";

    
 
    cerr << "Time elapsed: " << clock() - start << " ms\n";
    return 0;
}

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