Submission #419540

#	Time	Username	Problem	Language	Result	Execution time	Memory
419540		Kerim	Group Photo (JOI21_ho_t3)	C++17	12 / 100	504 ms	82436 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;}
int n,all;
const int N=20;
int dp[1<<N][N],arr[N],cost[N][N];
int rec(int mask,int last){
	if(mask==all)return 0;
	int &ret=dp[mask][last+1];
	if(~ret)return ret;
	ret=INF;
	int tmp;
	for(int i=0;i<n;i++)	
		if(!(mask>>i&1) and last<=i+1){
			tmp=0;
			for(int j=0;j<n;j++)
				if(mask>>j&1)
					tmp+=cost[j][i];
			umin(ret,rec(mask|(1<<i),i)+tmp);
		}
	return ret;
}
int main(){
   //freopen("file.in", "r", stdin);
	memset(dp,-1,sizeof dp);
	scanf("%d",&n);
	for(int i=0;i<n;i++)
		scanf("%d",arr+i),arr[i]--;
	for(int i=0;i<n;i++)
		for(int j=0;j<i;j++)
			cost[arr[i]][arr[j]]=1;
	all=(1<<n)-1;
	printf("%d\n",rec(0,-1));
	return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:42:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |  scanf("%d",&n);
      |  ~~~~~^~~~~~~~~
Main.cpp:44:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |   scanf("%d",arr+i),arr[i]--;
      |   ~~~~~^~~~~~~~~~~~

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