Submission #1231056

#	Time	Username	Problem	Language	Result	Execution time	Memory
1231056		hainam2k9	Group Photo (JOI21_ho_t3)	C++20	100 / 100	286 ms	165472 KiB

Main

#include <bits/stdc++.h>
#define tt cin.tie(0), cout.tie(0), ios_base::sync_with_stdio(0)
#define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
#define ll long long
#define ull unsigned long long
#define i128 __int128
#define db long double
#define sz(a) ((int)(a).size())
#define pb emplace_back
#define pf emplace_front
#define pob pop_back
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define ins emplace
#define mp make_pair
using namespace std;
const int MOD = 1e9+7, MAXN = 1e5+5;
const string NAME = "";
int n,a[5005],pos[5005],cnt[5005][5005],cost[5005][5005];
ll dp[5005];
int main()
{
    tt;
    if(fopen((NAME + ".INP").c_str(), "r")) fo;
    cin >> n;
    for(int i = 1; i<=n; ++i)
        cin >> a[i], pos[a[i]]=i;
    for(int i = 1; i<=n; ++i)
        for(int j = 1; j<=n; ++j)
            cnt[i][j]=cnt[i][j-1]+(a[j]>=i);
    for(int i = 1; i<n; ++i)
        for(int j = i+1; j<=n; ++j)
            cost[i][j]=cost[i][j-1]+cnt[i][pos[j]]-cnt[j][pos[j]];
    memset(dp,0x3f,sizeof(dp));
    dp[0]=0;
    for(int i = 1; i<=n; ++i){
        ll c=0;
        for(int j = i; j>0; --j){
            c+=cnt[i+1][pos[j]];
            dp[i]=min(dp[i],dp[j-1]+c+cost[j][i]);
        }
    }
    cout << dp[n];
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:3:19: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:27:45: note: in expansion of macro 'fo'
   27 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~
Main.cpp:3:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |                                                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:27:45: note: in expansion of macro 'fo'
   27 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~

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