Submission #971218

#	Time	Username	Problem	Language	Result	Execution time	Memory
971218		Abito	Line Town (CCO23_day1problem3)	C++17	0 / 25	1 ms	4444 KiB

Main

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define ep insert
#define endl '\n'
#define elif else if
#define pow pwr
#define sqrt sqrtt
#define int long long
#define ll long long
#define y1 YONE
#define free freeee
#define lcm llcm
typedef unsigned long long ull;
using namespace std;
const int N=5e5+5,M=1e6+3;
int a[N],n,dp[N][3];
bool vis[N][3];
int rec(int i,int j){
    //cout<<i<<' '<<j<<endl;
    if (i==n+1) return 0;
    if (vis[i][j+1]) return dp[i][j+1];
    dp[i][j+1]=INT_MAX;
    vis[i][j+1]=1;
    if (a[i]>=j) dp[i][j+1]=min(dp[i][j+1],rec(i+1,a[i]));
    if (a[i]<j){
        if (a[i+1]==a[i]) dp[i][j+1]=min(dp[i][j+1],rec(i+2,1)+1);
        else return dp[i][j+1]=INT_MAX;
    }
    if (a[i]==j && a[i]==-1) dp[i][j+1]=min(dp[i][j+1],rec(i+1,1)+1);
    return dp[i][j+1];
}
int32_t main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
    cin>>n;
    for (int i=1;i<=n;i++) cin>>a[i];
    int x=rec(2,a[1]);
    if (x>=INT_MAX) x=-1;
    cout<<x<<endl;
    return 0;
}

• Subtask 1: 0 / 3
• Subtask 2: 0 / 3
• Subtask 3: 0 / 3
• Subtask 4: 0 / 4
• Subtask 5: 0 / 4
• Subtask 6: 0 / 3
• Subtask 7: 0 / 2
• Subtask 8: 0 / 3