Submission #861190

#	Time	Username	Problem	Language	Result	Execution time	Memory
861190		Requiem	Global Warming (CEOI18_glo)	C++17	100 / 100	52 ms	10132 KiB

glo

#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#define MOD 1000000007
#define INF 1e18
#define fi first
#define se second
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define FORD(i,a,b) for(int i=a;i>=b;i--)
#define sz(a) ((int)(a).size())
#define pi 3.14159265359
#define TASKNAME "globalwarming"
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; } 
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; } 
using namespace std; 
typedef pair<int,int> ii; 
typedef pair<int,ii> iii; 
typedef vector<int> vi; 
const int MAXN = 2e5 + 9;
int a[MAXN],lisright[MAXN],lisleft[MAXN];
int n,x,lis[MAXN],dp[MAXN];

main() 
{ 
    fast; 
    // freopen(TASKNAME".inp","r",stdin); 
    // freopen(TASKNAME".out","w",stdout); 
    cin>>n>>x;
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    memset(lis,0x3f,sizeof(lis));
    for(int i=1;i<=n;i++){
        int l=1,r=n,res=0;
        while(l<=r){
            int mid = (l+r)>>1;
            if (lis[mid] < a[i]){
                res = mid;
                l = mid + 1;
            }
            else r = mid - 1;
        }
        lis[res+1] = a[i];
        lisleft[i] = res + 1;
    }
    for(int i=1;i<=n;i++){
        a[i] -= x;
    }
    memset(lis,-0x3f,sizeof(lis));
    for(int i=n;i>=1;i--){
        int l=1,r=n,res=0;
        while(l<=r){
            int mid = (l+r)>>1;
            if (lis[mid] > a[i]){
                res = mid;
                l = mid + 1;
            }
            else r = mid - 1;
        }
        lisright[i] = res + 1;
        a[i] += x;
        l=1,r=n,res=0;
        while(l<=r){
            int mid = (l+r)>>1;
            if (lis[mid] > a[i]){
                res = mid;
                l = mid + 1;
            }
            else r = mid - 1;
        }
        lis[res+1] = a[i];
    }
    // for(int i=1;i<=n;i++){
    //     cout<<lisleft[i]<<' ';
    // }
    // cout<<endl;
    // for(int i=1;i<=n;i++){
    //     cout<<lisright[i]<<' ';
    // }
    // cout<<endl;
    int ans = 0;
    for(int i=1;i<=n;i++){
        ans=max(ans, lisleft[i] + lisright[i] - 1);
    }
    cout<<ans<<endl;
    
} 

Compilation message (stderr)

glo.cpp:24:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   24 | main()
      | ^~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 25 / 25