Submission #742472

#	Time	Username	Problem	Language	Result	Execution time	Memory
742472		jamielim	Tortoise (CEOI21_tortoise)	C++14	0 / 100	1 ms	340 KiB

tortoise

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb emplace_back
#define ALL(x) x.begin(),x.end()
#define SZ(x) (int)x.size()
typedef long long ll;
typedef pair<int,int> ii;
typedef pair<ii,ii> i4;
typedef vector<int> vi;
const int MOD=1000000007;
const int INF=1012345678;
const ll LLINF=1012345678012345678LL;
const double PI=3.1415926536;
const double EPS=1e-14;

int n,arr[500005];
vector<int> v;
int dist[500005];
int dp[305][605]; // max number of candies removed for (last shop taken from, time)

int main(){
	scanf("%d",&n);
	int sum=0;
	for(int i=0;i<n;i++){
		scanf("%d",&arr[i]);
		if(arr[i]==-1)v.pb(i);
		else sum+=arr[i];
	}
	for(int i=0;i<n;i++){
		if(arr[i]!=-1){
			int x=lower_bound(ALL(v),i)-v.begin();
			dist[i]=abs(v[x]-i);
			if(x!=0)dist[i]=min(abs(v[x-1]-i),dist[i]);
		}
	}
	if(arr[0]==1){
		for(int j=0;j<=600;j++){
			dp[0][j]=1;
		}
	}else{
		for(int j=0;j<=600;j++){
			dp[0][j]=-INF;
		}
	}
	for(int i=1;i<n;i++){
		if(arr[i]==1){
			for(int j=0;j<=600;j++){
				if(j<i)dp[i][j]=0;
				if(j==i)dp[i][j]=1;
				if(j>i){
					dp[i][j]=1;
					for(int k=0;k<i;k++){
						if(j>=dist[i]+dist[k]){
							dp[i][j]=max(dp[i][j],dp[k][j-dist[i]-dist[k]]+1);
						}
					}
				}
			}
		}else{
			for(int j=0;j<=600;j++)dp[i][j]=-INF;
		}
	}
	printf("%d",sum-dp[n-1][2*n-2]);
}

Compilation message (stderr)

tortoise.cpp: In function 'int main()':
tortoise.cpp:26:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |  scanf("%d",&n);
      |  ~~~~~^~~~~~~~~
tortoise.cpp:29:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |   scanf("%d",&arr[i]);
      |   ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 25
• Subtask 5: 0 / 27