Submission #419699

#	Time	Username	Problem	Language	Result	Execution time	Memory
419699		Kerim	Group Photo (JOI21_ho_t3)	C++17	44 / 100	2722 ms	836 KiB

Main

#include "bits/stdc++.h"
#define MAXN 100009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace std;
 
typedef long long ll;
typedef pair<int,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
const int N=202;
int n,arr[N],inv[N][N],dp[N][N];
int F[N][N];
int g(int x,int y){
	int res=0;
	for(int i=y;i>=x;i--)
		for(int j=i-1;j>=x;j--)
			res+=inv[i][j];
	return res;
}
int f(int x,int y,int xx,int yy){
	int res=0;
	for(int i=x;i<=y;i++)
		for(int j=xx;j<=yy;j++)
			res+=inv[i][j];
	return res;
}
int pre(int x,int y,int z){
	int res=0;
	for(int i=x;i<=y;i++)
		res+=inv[i][z];
	return res;
}
int suf(int z,int x,int y){
	int res=0;
	for(int i=x;i<=y;i++)
		res+=inv[z][i];
	return res;
}
int cost(int a,int b,int c){
	int res=g(a+1,b-1)+F[a][b-1]+suf(b,a+1,b-1);
	if(c)res+=pre(1,b,c);
	return res;
}
int rec(int a,int b){
	if(b==n)return cost(a,b,0);
	int &ret=dp[a][b];
	if(~ret)return ret;
	ret=INF;
	for(int i=b+1;i<=n;i++)
		umin(ret,rec(b,i)+cost(a,b,i));
	return ret;
}
int main(){
	//freopen("file.in", "r", stdin);
	memset(dp,-1,sizeof dp);
	scanf("%d",&n);
	for(int i=1;i<=n;i++)scanf("%d",arr+i);
	for(int i=2;i<=n;i++)
		for(int j=1;j<i;j++)
			inv[arr[i]][arr[j]]++;
	for(int y=1;y<=n;y++)
		for(int z=y+1;z<=n;z++){
			F[y][z]=F[y][z-1];
			for(int x=1;x<=y;x++)
				F[y][z]+=inv[x][z];
		}
	int ans=INF;
	for(int i=1;i<=n;i++)
		umin(ans,rec(0,i));
	printf("%d\n",ans);
	return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:66:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |  scanf("%d",&n);
      |  ~~~~~^~~~~~~~~
Main.cpp:67:28: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |  for(int i=1;i<=n;i++)scanf("%d",arr+i);
      |                       ~~~~~^~~~~~~~~~~~

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